Decoding Archaeological Spaces: A Space Syntax Study of the Hellenistic Baths in Syracuse

1. Introduction

Hellenistic Greek cities were distributed across the Mediterranean, spanning the Greek mainland, the Aegean, Asia Minor, the eastern Mediterranean, and the western Mediterranean (Kemezis 2015; Larguinat-Turbatte 2018). Public baths were an important architectural institution in Hellenistic Greek cities, serving not only hygienic but also social and cultural functions. The internal circulation pattern and spatial hierarchical structure of the building have largely shaped the methods of use and social patterns of the public baths (Krencker & Krüger 1929; Nielsen 1990).

Previous research on Hellenistic baths has focused on excavation results, typological classification, and historical interpretation, and has provided valuable insights into construction techniques and urban context (Holloway 2002). However, these studies rarely employ quantitative methods that can analyze spatial layout as a variable. Moreover, the relationship between the architectural layout of public bathing rooms and social activities remains underexplored (Lucore 2013).

To address this gap, this study applies space syntax analysis, an established analytical framework for examining architectural space through quantitative and visual models (Hillier & Hanson 1984; Lorenzon, Pylkännen & Artto 2023). Developed by Bill Hillier and Julienne Hanson, space syntax enables the systematic investigation of spatial configuration by analyzing connectivity, Integration, and Visibility Graph Analysis (VGA), thereby treating architectural space as a structured system rather than a collection of isolated rooms (Ostwald 2011; Turner & Gardner 2015). Space syntax, an important analytical tool in archaeology for studying architectural spaces, has been shown to effectively decode the social logic of classical architectural spaces (Cortés & De Soto 2022; Lorenzon, Pylkännen & Artto 2023). It quantifies spatial indicators, translating abstract configurations into evidence for interpreting social practice, thus addressing the insufficient link between spatial data and social interpretation in traditional studies of Hellenistic baths.

Sicily is an island in southern Italy. In 734 BC, the ancient Greek city-state of Corinth established the colony of Syracuse on the southeastern coast of Sicily. It was part of ancient Greek colonial expansion (Figure 1). Meanwhile, numerous important independent Greek cities existed in Sicily, such as Morgantina, Gela, Megara, and Hyblaea. As economic prosperity and urban development increased, city rulers invested in public infrastructure to improve residents’ quality of life, including the construction of public baths (Lucore 2013).

Figure 1

Cicero, writing in 70 BC in the Verrine Orations, described Syracuse as “the greatest and most beautiful Greek city” (In Verrem 2.4.118). Cicero’s description underscores Syracuse’s prominence and cultural richness, making it an ideal case study for understanding the evolution of public baths in the Hellenistic world. According to Cultrera’s archaeological findings (Cultrera 1938), the Syracuse baths were undergoing renovation and expansion in 212 BC, when construction was stopped due to Roman occupation (Fagan 1999).

This study focuses on the Hellenistic baths of Syracuse (3rd century BC), a major urban complex developed during the reign of Hieron II. Comparative references to other bath complexes in Sicily and the Roman world are employed to contextualize the findings within broader Mediterranean bathing traditions.

By examining the spatial configuration of the baths through space syntax analysis, this article investigates how the layout of the Syracuse baths structured circulation patterns and spatial hierarchy. It further conducts comparative space syntax analyses of bath complexes at Morgantina in Sicily and the Baths of Trajan in Rome. The discussion section also includes a comparative examination of the architectural plan of the Tell el-Herr Baths in ancient Egypt (Fournet & Redon 2017).

Through these comparisons, the study addresses the following questions: “How did the architectural spatial organization of the Hellenistic baths in Syracuse reflect circulation patterns, potential social differentiation, and experiential sequences? What insights does it provide on the transformation of bathing cultures from Greece to Rome?”

2. History of investigation

3. Architectural Description

The ancient public baths of Syracuse are situated along the modern Via Zappalà, adjacent to the northern side of the Neapolis district — the “New City” — one of the city’s four main districts. Neapolis is in the northwest of the city center and was the principal cultural and entertainment district in the Hellenistic period. The other three districts are: the oldest district, Ortigia; the commercial and residential district, Achradina; and the religious and burial district, Tyche.

This location, in the immediate vicinity of the Greek Theatre, suggests that the baths primarily served the city’s middle-class residents for both hygiene and social engagement. The Tomb of Archimedes is near here. Only the core area of the baths has been excavated (Basile & Crispino 2017). The Zappalà area was densely populated, with cemeteries dating from the 4th century BC into the late Roman period.

The excavated area covers approximately 900 square meters, with the bath complex measuring 35 meters in length and 25 meters in width. The site includes 21 rooms, such as aisles (d), dressing rooms (o, q), a heated communal immersion pool (h), a luxury bathing room (g), tholos (f, k), basin or pool (i), furnace (j), and storage area(c), arranged around a central corridor.

Two entrances can be found in the bath complex. One of these, thought to be the main entrance, is on the eastern side. It opens from the rectangular reception hall into space e, then runs through spaces o and q before reaching aisle d. A small storage room can be found on the southern side of aisle d. Beyond this space a U-shaped corridor leads farther into the main bathing zone. On the right side, at the far end of this corridor, a bathing room (g) is located. Within this room, stone benches run along the northern and eastern walls. These benches are 6.0 meters long, 1.2 meters wide, and 0.5 meters deep, and would have accommodated approximately 6 to 8 people for bathing together. The heated communal immersion pool (h) extends west of the bathing room (g). Behind this pool sits a second basin (i), which is similar in both scale and function (Cultrera 1938; Figure 2).

Figure 2

Archaeologists have identified a secondary entrance on the bath complex’s western side, directly opposite the main entrance. Significantly, deep wheel ruts preserved at this entrance suggest it likely functioned as the principal access to an adjacent cemetery. From this western entrance, a 9.0- meter-long and 2.0-meter-wide passage (p) leads inward. A right turn opens into the furnace room (j), which was serviced by a subterranean hot-water pipe. Beyond lies the striking western tholos (k), its perimeter lined with individual terracotta-tile bidets. This circular room also connects eastward to room d, which in turn links to the bath complex’s eastern half and provides access to a second tholos (f). Within these spaces, the two central pillars not only provided essential structural support, but also — as Lucore (2009) argues — may have been adapted to enhance the bathing ritual, possibly serving as stations for assisted washing or even massage (Lucore 2009).

Taken together, these spatial components and circulation paths reveal the baths’ carefully planned design. Beyond their layout and functional arrangements, the Syracuse Baths are distinguished by innovative structural features.

4. Structure

The baths of Syracuse are defined by two major advances in architectural design: a novel, luxurious model of heated communal bathing (g, h) and the earliest recorded use of complex domed and vaulted structures (k, f) (Lucore 2013).

Most public baths in Sicily had a rectangular plan with a central circular sitting room, but Syracuse is the only bath known to have two circular rooms. The furnace built in the middle of the baths is also an architectural feature of Sicilian baths. These large heating systems, often referred to as bottle systems, pass hot water through spliced terracotta bottles and drain it. Although a nearby water channel has been discovered, it remains unclear how the bathhouse accessed such a substantial water source. The two circular vaults in the center of the bathhouse are also constructed from tiled pipes. The interior of the bathhouse has been plastered. Archaeologists did not find a caldarium, tepidarium, or frigidarium in Syracuse, a significant departure from the typical layout of ancient Roman baths (Delaine 1989; Lucore 2013). After entering the baths, people went straight to the hot baths. This architectural plan is also reflected in the public baths of the same period in Sicily (Lucore et al. 2021).

5. Space syntax analysis

While the preceding section outlines the architectural characteristics of the Syracuse baths, these features alone do not fully reveal their spatial organization. To examine this issue systematically, the following section applies space syntax analysis, beginning with an explanation of the calculation procedures before comparing the topological layouts and data of three bath complexes.

5.1 Calculation Procedure

In theoretical research on space syntax, a complex architectural space is first converted into Justified Plan Graphs (JPGs), which represent the topological relationships between spaces and provide the basis for subsequent quantitative analysis (Ostwald 2011). In archaeological applications, JPGs have been widely used to formalize spatial depth, accessibility, and hierarchical relationships within buildings, allowing architectural plans to be analyzed as structured spatial networks rather than as purely geometric drawings (Fladd 2017).

In this study, the bath complexes were converted into JPGs by defining each enclosed room or functional space as a node and each direct spatial connection as an edge. The main entrance of the bath was selected as the root node, reflecting its primary role in regulating access and circulation (Figure 3). All other spaces were then assigned depth levels (D) based on their topological distance from this entrance, yielding a hierarchical representation of spatial organization (Letesson 2013). Based on these JPGs, several key space syntax metrics were calculated. Total depth (TD) was computed by summing the depth values of all nodes (nX) relative to the entrance, following standard formulations in archaeological space syntax studies. TD values for the different rooms of the Syracuse Baths are presented in Table 1. The calculation follows (Ostwald 2011):

1

$\text{TD} = \left(0 \times \text{n}0\right) + \left(1 \times \text{n1}\right) + \left(2 \times \text{n2}\right) + \dots + \left(\text{X} \times \text{nX}\right)$

Table 1

Data analysis of the Syracuse Baths (calculated by the authors).

SPACE ID	CONNECTIVITY	CV	TDn	MDn	INTEGRATION	RA	RRA
1	1	0.5	112	5.89474	0.413864	0.54386	2.41625
8	1	0.5	108	5.68421	0.442407	0.520468	2.31233
16	1	0.25	96	5.05263	0.499862	0.450292	2.00055
18	1	0.25	96	5.05263	0.499812	0.450292	2.00055
2	2	1.25	94	4.94737	0.513192	0.438596	1.94859
0	1	0.25	92	4.84211	0.542104	0.426901	1.89663
15	1	0.5	92	4.84211	0.675252	0.426901	1.89663
19	1	0.25	92	4.84211	0.542104	0.426901	1.89663
7	2	1.25	90	4.73684	0.557817	0.415205	1.84466
13	1	0.333333	86	4.52632	0.574468	0.391813	1.74074
3	1	0.25	82	4.31579	0.630973	0.368421	1.63682
12	1	0.25	82	4.31579	0.630973	0.368421	1.63682
17	4	2.83333	78	4.10526	0.652362	0.345029	1.53289
4	4	2.74	74	3.89474	0.726215	0.321637	1.42897
14	2	1.3333	74	3.89474	0.675252	0.321637	1.42897
11	3	1.75	68	3.57895	0.785498	0.28655	1.27308
5	4	2.75	64	3.36842	0.895102	0.263158	1.16915
10	2	0.666667	62	3.26316	0.895102	0.251462	1.11719
6	2	0.583333	60	3.15789	0.986907	0.239766	1.06523
9	3	1.5	58	3.05263	0.986907	0.22807	1.01327

Figure 3

Connectivity, Integration, and Visibility Graph Analysis (VGA) are the most frequently mentioned and used parameters in space syntax theory and quantitative analysis.

Connectivity indicates the number of direct spatial adjacencies within a building, and thus reflects spatial hierarchy. A higher connectivity value corresponds to greater spatial permeability, while a lower value indicates more restricted access and poorer circulation potential (Stöger 2009; Figure 4A, D, G).

Figure 4

Integration reflects the degree to which space is positioned centrally within the overall system and thus reveals underlying circulation patterns. It is widely used to assess the extent to which space is embedded within a spatial system and its capacity to shape movement and access. Spaces with higher integration values tend to be more accessible and central, whereas those with lower values are more segregated and peripheral, with limited impact on broader circulation (Criado-Perez et al. 2020).

However, integration values are fundamentally derived from mean depth (MD) and are therefore sensitive to variations in system size and topological complexity (Table 1). Direct comparisons of raw integration values across buildings with different numbers of spaces and depth structures can be misleading. To address this problem, Real Relative Asymmetry (RRA) is used as a normalized measure that adjusts mean depth relative to system size, enabling valid comparisons between buildings of different scales. RRA values for the individual rooms of the Syracuse Baths are reported in Table 1. Calculations of integration and RRA follow the standard formulations set out by Ostwald (2011), as shown in Equation 2–5.

2

$\text{RA}\_\text{i} = \frac{2(\text{MD}\_\text{i} – 1)}{\text{n} – 2}$

3

$\text{D}\_\text{n} =\frac{2\{\text{n}[{log}_2\left(\right(\text{n} + 2)/3 ) – 1 ] + 1 \}}{(\text{n} – 1)(\text{n} – 2)}$

4

$\text{RRA}\_\text{i} = \frac{\text{RA}\_\text{i}}{\text{D}\_\text{n}}$

5

$\text{I} = \frac{1}{\text{RRA}\_\text{i}}$

Visibility Graph Analysis (VGA) models lines of sight by accounting for architectural boundaries and human visual parameters, generating visibility values that range from blue (low visibility) to red (high visibility) across the spatial field. VGA has been increasingly applied in archaeological research to explore movement, perception, and the experiential qualities of built environments (Stöger 2007; Turner & Gardner 2015). In the present study, visibility values are examined alongside circulation routes and depth levels to understand how visual accessibility may have shaped movement and social interaction within the baths. Notably, visual access patterns captured by VGA may also reflect patterns of social differentiation. The computational procedures employed in the analysis are illustrated in Figure 5 (Cortés & De Soto 2022; Lorenzon, Pylkännen & Artto 2023).

Figure 5

6. Discussion

The following discussion addresses three interrelated issues concerning the spatial organization of Hellenistic and Roman bath complexes.

The first issue concerns how the baths of Sicily evolved into the architectural layout of the Baths of Trajan in Rome. A Ptolemaic (Greek) bath complex was unearthed at Tell el-Herr in Ismailia, Egypt (near the Nile Delta), during excavations conducted by French archaeologists (Fournet & Redon 2017). This is a typologically transitional public bath building, representing an intermediate stage in the evolution of bathing architecture from the Hellenistic to the Roman era.

Like the baths on the island of Sicily, the Tell El-Herr baths retained circular bathing rooms. However, unlike those on Sicily, the Tell El-Herr baths placed the circular and rectangular heated rooms in two separate, parallel spaces, each with its own one-way straight-line route, and these two systems did not intersect. Tell El-Herr baths’ layout resembles two simple, tree-shaped structures. It does not achieve the fully integrated, symmetrical layout characteristic of Roman imperial baths, but lies in between the Sicilian baths and the Baths of Trajan (Figure 6).

Figure 6

From this perspective, the Tell El-Herr baths demonstrate how the circular bathing rooms, originally embedded within a tree-shaped spatial structure, were replanned as parallel, independent circulation systems. This architectural layout provides important evidence for understanding the spatial and social reconfiguration of bathing customs in the Mediterranean region during the transition from the Hellenistic to the Roman era (Figures 3 and 6).

The second issue concerns the distinction between tree-shaped and ring-shaped structures in ancient public baths. According to Ostwald (2011, 460, figs. 11–12), spatial structures can be broadly classified as tree-shaped or rhizomorphous. In the present study, the latter is referred to as a ring-shaped structure to emphasize its circular circulation and integrated spatial organization.

From a behavioral perspective (Osborne 2012), tree-shaped structures often support controlled, hierarchical, and possibly ritualized usage patterns, while ring-shaped structures facilitate parallel circulation, social interaction, and flexible use of space. By comparing spatial grammatical indicators (Figures 4 and 5), we can also obtain empirical evidence.

In the dendritic spatial structure, the space gradually deepens vertically, while the horizontal connectivity between rooms is restricted, and the terminal spaces are mostly isolated from each other. This explanation is confirmed by the spatial grammatical indicators. For example: in the Syracuse and North Morgantina baths, the highest values of connectivity and integration are concentrated at the corridor nodes rather than in the bathing rooms, indicating that movement and control are concentrated in specific areas of the space rather than being uniformly distributed (Figure 4 and Table 1). There, entering the bathing room requires passing through a limited number of control nodes, thereby reinforcing the sequential movement and the hierarchical structure of the space (Figure 7 top; Ostwald 2011).

Figure 7

In contrast, the ring-shaped spatial structure has a shallower depth but enhances the visibility and accessibility between rooms. Through symmetrical or ring-shaped layouts, these structures provide multiple pathways for movement and promote spatial transparency. For example, in the space syntax analysis diagram of the Trajan Baths (Figure 5), this logic is reflected in the distribution of integration and visibility values, with the peak not occurring in a specific commonly used room (such as the hot water room), but at the open-air swimming pool located on the central axis. This indicates a shift from a controlled to an integrated space, allowing many users to gather and interact simultaneously, and reflects the broader strategy of managing social diversity within a unified architectural framework (Figure 7 bottom; Ostwald 2011).

The third issue concerns the relationship between spatial layout, functional complexity, and social relations in public baths.

7. Conclusions

Through a syntactic analysis of the spaces of the Syracuse baths, the North Morgantina baths, and the Baths of Trajan, a key finding of this study is that tree-shaped and ring-shaped spatial prototypes appear to represent not merely abstract classificatory forms, but plausible spatial logics that may have structured bathing practices from the Hellenistic to the Roman period. Based on previous research (Krencker & Krüger, 1929; Nielsen, 1990), the present research empirically assesses the applicability and explanatory potential of established spatial topological models using four archaeological cases. This approach provides a consistent empirical foundation for investigating the long-term developmental trajectory of bathing architecture from the Hellenistic to the Roman periods.

The Hellenistic baths of Sicily consistently display a tree-shaped structural organization. This pattern is marked by a strong axial sequence leading into deeper spaces, limited lateral connectivity, and structured circulation via controlled corridor access. By contrast, large-scale imperial Roman baths tend to employ more symmetrical, ring-shaped plans and highly integrated spatial layouts that appear conducive to parallel circulation, intensive co-presence, and expanded social interaction. Comparison with the Tell El-Herr baths in Egypt further suggests that the shift between these two prototypes was gradational, unfolding through intermediate forms in which ring-shaped configurations emerged from tree-structured systems and reorganized into parallel, semi-independent circulation pathways.

A typological comparison across the four sites indicates a further significant finding: these spatial prototypes are not determined solely by building size but instead correlate closely with functional complexity and social orientation. Although the Syracuse baths are relatively modest in scale, their tree-shaped layout is consistent with bathing practices structured around ordered movement and spatial differentiation. By contrast, the monumental scale of the Baths of Trajan entails not only greater functional complexity, but also a qualitatively distinct spatial logic that seems oriented toward integrating diverse activities and user groups within a unified architectural framework.

Finally, while space syntax cannot directly verify specific social categories such as gender or class, it offers a rigorous method for linking values of integration, relative asymmetry (RRA), and visibility. This allows bath complexes of differing scale, date, and preservation to be compared within a shared analytical framework. By revealing how architectural layout may have facilitated or constrained movement, encounter, and visibility, Space syntax permits a more structured and critical evaluation of the spatial and temporal plausibility of social interpretations — including those concerning gender and class. In this way, it provides a valuable methodological reference for archaeologically grounded spatial research.

Crucially, however, space syntax illuminates spatial potential rather than empirically proven use. Its results support plausible inferences about social practice, but cannot independently confirm the actual identities, behaviors, or social dynamics at play. Future work incorporating more detailed archaeological evidence, refined architectural reconstructions, and expanded regional comparisons will further test, validate, and refine this quantitative approach.

Data Accessibility Statement

Access to the spatial data and analysis outputs generated in this study using Depthmap is restricted for reasons of ongoing research. They can be made available from the corresponding author upon reasonable request.

Declaration of AI use

Language was improved with the assistance of Grammarly (v1.2.243.1862).

Author Contributions

Yang Mei (First Author)

Formulated the core research topic and theoretical framework focused on Roman architectural archaeology, defined research objectives, and integrated the methodological approach. Led the in-depth analysis of Roman architectural remains, spatial patterns, and contextualization within urban archaeological frameworks. Directed archival and archaeological literature research, including critical evaluation of early excavation records. Drafted the full manuscript, including literature review, data analysis, discussion, and conclusion sections. Designed and prepared all figures, tables, and architectural graphical materials for the manuscript.

Ji Zhiwei (Corresponding Author)

Provided access to relevant archaeological archives, literature resources, and supplementary research materials. Performed detailed research on early excavations, architectural documentation, and relevant archaeological literature.

Classical Sources

Cicero. In Verrem. Translated by L.H.G. Greenwood. Loeb Classical Library. Harvard University Press, 1928.