The old town was built from the 13C onwards by the Venetians, who enclosed it behind walls rebuilt in the 16C to the plans of the great engineer Sanmicheli; a few vestiges are still standing. Don't miss the Kastéli District, which was the site of ancient Kydonia, a rival of Knossós, and the Merchants' District which houses the Naval Museum (historic documents and model ships) and contains old Venetian houses (some doorways have carved coats of arms and mottoes).