Despite successive attacks and relentless bombardments during the twenty-year siege by the Ottomans, the fortifications of Candia survived into modern times almost intact, with only minor interventions during the Ottoman period. In 1931 they were officially designated a historic listed monument (Presidential Decree of 8 June 1931 – Government Gazette 159/A/13-6-1931).

However, from the early 20th century onwards, the fortifications increasingly came to be regarded as an obstacle to the urban development of the modern city. The need to allow the passage of wheeled vehicles towards areas outside the walls and into the countryside led to the demolition of sections of the fortifications near the old gates.

In 1936, a new city plan was published in the Government Gazette. This plan proved to be disastrous, as it radically altered the urban fabric that had preserved the layout of the Venetian period, effectively erased the historic city centre, and degraded its monuments. The plan remains legally in force to this day, although it has never been fully implemented. As part of its application, the earthen embankment on the city side of the walls was cut back at various points, embankments were created to form broad avenues, and open spaces adjoining the earthen slopes of the fortifications were designated as building blocks and subsequently built over, depriving the monument of vital space.

The moat in front of the eastern lobe of the Vitturi Bastion received the debris from the earthquake of 1810 and continued to be gradually filled in up to the level of the parapet. Eventually, in 1917, the Georgiadis Park and part of Demokratias Avenue were laid out on this site.

In the early 1930s, the harbour zone underwent extensive interventions for the construction of a seafront avenue and a new pier. During these works, most of the Venetian shipyards, along with the gate of the same name and the small fort at the end of the southern breakwater—known as the “Little Koules”—were destroyed.

The expansion and densification of the urban fabric from the first decades of the 20th century often resulted in the occupation of open spaces on the upper, level areas of the walls and within the moat. Characteristic examples include neighbourhoods that developed on the sites of fortifications located outside the moat, which were demolished and eventually declassified in 1981. Part of the large fortification of Saint Demetrios to the east survived; upon it the Analipsi district developed, and the “Kapetanakeio” foundation was established.

After the war, the Freedom Stadium was installed within the moat between the Bethlehem and Pantokrator bastions. Football facilities were placed on the level area of the Martinengo Bastion, while tennis courts were installed on the Sabbionara Bastion and within its moat.