The church of St. Mark, dedicated to the patron saint of Venice was the official Venetian church of the city of Candia. Its construction began in 1239. It is a three-aisled basilica with a portico on the west side, where there was the entrance from the Morosini fountain in the Lion Square. It also had an impressive bell tower. When the city was conquered by the Turks, the church’s frescoes were destroyed, the bell tower was demolished.

A minaret was built in its place, and the church was converted into a mosque. In 1956 repairs began to restore the damage that the church had suffered over recent years, and it served as venue hosting cultural events. Today it houses the Heraklion Municipal Art Gallery which displays contemporary works by Cretan artists. Cultural events are also hosted here.