The Piatta Forma Bastion was built in the middle of the south side of the Venetian fortifications. It was in front of the Bastion of Santa Lucia to the east and of the bastion of St. Dimitrios to the west, while it was protecting the main city gate, the Porta Retimiotta (the gate of Rethymno). It had a rectangular shape and a salient into the trench.
On both sides there were two high rampart built with strong walls. The eastern rampart was called Santa Maria, from the monastery of Santa Maria della Missericordia on Hatzi Michalis Ntaliani Street, and the western one was called San Giovanni, from the name of the other church.
During the Cretan State the need of integration of the old and new city led to the demolition of this bastion. The demolition was decided in 1903 and began in 1908 for the construction of the Municipal Market. The trench was covered and the stones, with which the bastion was manufactured, were used for the construction of the building. Finally, the construction of the Market began in 1911 and it was inaugurated by the Prime Minister Eleftherios Venizelos on December 4, 1913.
