The last Venetian fortification of Chania was begun in 1536 by Sammicheli, the same architect who designed the fortifications of Iraklion. The fortifications of Chania were almost square in shape, with four bastions and two gates. Inside the fortifications there was a second fortifying wall surrounding the Kastelli, where there were a large number of Venetian palaces. Chania always had adequate water for its inhabitants. In 1645, after two months of Turkish siege and heroic battles, the walls near the rampart of Shiavo (southwest rampart) were cracked and the city was surrendered. Today the fortifications of Chania are visible in several locations around the city.