Halkidiki may offer many options for swimming and marine activities in the crystal-clear waters of its coasts, but there is a completely different landscape that attracts visitors: The unique lake of the peninsula, with the enchanting flora and environment, with its ravines and, the rare sea turtles it hosts. "Mavrobara", is a small natural lake in the forest of Polychronos, with an area of 2,200 square meters, at an altitude of about 200 meters. It is 3 km from the beach of Polychrono and 4 from Kassandrino. As a stopover, it is recommended for a walking route between the two points, while the descent from Kassandrino to the sea is an ideal downhill experience for cycling. The circular, easily accessible path around the lake is 3.2 km long and is full of colorful vegetation that changes every season, with benches and points for relaxation and observation of the lake. Mavrobara is a wetland starring turtle, and its visitors, especially when there are children for whom the lake is a fun attraction, are invited to have bread with them to feed them. In Mavrobara live, among others, three rare species of water turtles: the orbicularis, the Balkan Pond turtle, and Hermann's tortoise. It has been designated a Nature Monument since 1997.