Abstract
The following article presents the results of analyses of source materials regarding the presence of a defense work in the city space and the results of one case – the Warsaw Fortress System. Information on the characteristics of the fortified landscape was presented, with particular reference to one of the types of fortifications – the ring fortress. A very important element was to trace the history of this object and its changes in the last 150 years. Individual objects characterized by interesting architecture, terrain and interesting vegetation perform different functions in the city landscape. These functions result primarily from the different use of objects. It is also evident that these objects in the future may also develop as a result of adaptation to new purposes or use. They have a very large spatial and natural potential.