The artificial lake of Agia (Ayia) is located near the village of Agia, 9 km west of Chania. It is a small lake of 450 acres, which is close to the valley of Fasas. This valley is considered as the most humid of Crete. Agia lake receives water from underground springs and the river Xekolomenos.
The lake was a swamp before the Power Public Corp turned it to artificial, for producing hydroelectric power. Today, the power station is abandoned, but visitors still can see the old mechanisms.
This small lake hosts the largest variety of aquatic plants in Crete, but also hosts very important species of fauna, such as rare species of ferns and frogs. Moreover, the lake is a shelter for many migratory and non-migratory birds. The ecological significance of Ayia is reflected in the fact that it is protected.
In recent years, the irrigation works in the region have reduced the size of the lake, which has become a swamp in many places. Moreover the wetland has faced a tremendous alteration, after the introduction of the American bullfrog by a mindless businessman, that has today displaced the endangered Cretan water frog. Moreover, the introduced latinamerican weed Papsalum distichum has displaced the local flora and efforts are being to remove that from the lake.