Lake Seliger is the biggest lake of the Valdai Hills. The length of the lake from the north to the south is 90 km and from the west to the east is 50 km. The maximum depth is 24 m. The lake formed at the end of the fourth Ice Age. Near the lake there is an ancient town of Ostashkov. The town was firstly mentioned in 1477 and has a rich history.The Troitsky cathedral (1697) is one of the best architectural monuments of the Seliger. The Regional Museum is located in the cathedral. In the belfry of the cathedral there is an exposition of Ostashkov’s bells.
The most famous place on the lake Seliger is the monastery Nilova Pustin. It is situated on the Stolbny Island. It is a small flat island, so the magnificent monastery buildings appear to be standing on water. A bridge connects the island with the mainland.
In summer 1528 hermit Nil secluded himself on a deserted island Stolbovoy. At first he lived in a cave that he dug in the mountain, then built a small wooden cell-hut and a chapel. The holy man’s prayers healed the sick, tamed the waves on the Seliger. St. Nil lived on Stolbovoy for 27 years. The monastery was founded in 1591. The relics of St. Nil lie in a wooden shrine in the Bogoyavlensky cathedral. The oldest construction of the monastery is the Church of All Saints (the 17th century).