Water was of crucial importance if the city was to withstand a siege, therefore the townspeople took appropriate measures. The Great Cistern of New Pleuron, within the city walls, is an unforgettable example of water management projects. It has a depth of 7.2m and a capacity of 2,500 cubic meters. Initially the site was probably used as a quarry; the stones were used to construct the walls and the buildings of the city. When construction was finished, the quarry was used for water storage. The cistern consists of five compartments separated by stone walls. One of the compartments was roofed with stone slabs (one remains in place) while the others were covered with a tile roof.