Fig 1.
Evolution of the Original Sites of Fortifications in Krasnye Vorota Square, Moscow: (a) Plan of Krasnye Vorota Square in 1800, before the demolition of the fortifications; (b) Plan of Krasnye Vorota Square in 1852, where the original sites of fortifications were converted into the Garden Ring Road with gardens; (c) Plan of Krasnye Vorota Square in 1960, when the Garden Ring Road was widened, and the former gardens disappeared; (d) Plan of Krasnye Vorota Square in 2024, where the lanes of the Garden Ring Road were narrowed, pedestrian walkways were expanded, and gardens increased.
Fig 2.
Diagram of the Gargon Ring Transformation in Moscow.
Fig 3.
Evolution of the Original Sites of Fortifications in the Porte de Vanves Area, Paris: (a) Plan of the Porte de Vanves area in 1912, before the demolition of the fortifications; (b) Urban planning map of the Porte de Vanves area in 1924, designed by Louis Bonnier; (c) Plan of the Porte de Vanves area in 1975, where part of the planned green belt was occupied by the Boulevard Périphérique, as well as residential and public buildings; (d) Plan of the Porte de Vanves area in 2024, where parts of the Boulevard Périphérique have been covered and transformed into public spaces.
Fig 4.
Diagram of the Paris Boulevard Périphérique Transformation.
Fig 5.
Strategies for Improvement the Original Sites of Fortifications in Paris.
Fig 6.
Evolution of the Original Sites of Fortifications in the Chaoyangmen Area, Beijing: (a) Plan of the Chaoyangmen area in 1949, before the city walls were demolished; (b) Planning map of the original site of the city walls in the Chaoyangmen area in 1962; (c) Plan of the Chaoyangmen area in 1996, showing the moat being buried and the construction of high-rise buildings beginning on the outer side of the Second Ring Road; (d) Plan of the Chaoyangmen area in 2024, showing a significant increase in green space, with Siheyuan inside the Second Ring Road replaced by high-rise buildings.
Fig 7.
Strategies for Improvement the Original Sites of Fortifications in Beijing.
Fig 8.
Functional Distribution Diagram of the Original Sites of Fortifications in Three Cities Across Different Stages.
Fig 9.
Diagram of Changes in Internal Functional Proportions of the Original Sites of Fortifications in Three Cities.
Fig 10.
Time Division of the Three Stages of the Original Sites of Fortifications in Three Cities.
Table 1.
Comparison of Basic Information on Fortifications of Three Cities.
Table 2.
Comparison of Urban Ring Roads Built on the Original Sites of Fortifications in Three Cities.