The famous landmark of Agios Nikolaos is the small, circular lake known as 'Voulismeni' in the centre of the resort. It is linked to the sea by a narrow canal, which greatly adds to the beauty of the lake, while its natural surroundings (red rocks within green plants) make it a wonderful sight.
According to mythology, the goddess Athena used to take her bath in this lake and it was believed by many that the lake was bottomless. However, a depth reading done by an English sea captain, calculated the lake to be 64 metres deep. It is especially picturesque area with an assortment of open-air cafes and restaurants.