White Sea small. The main island group is the Solovetsky Islands, located almost in the middle of the sea, near the entrance to Onega Bay. Kiy Island in Onega Bay is significant due to a historic monastery. Velikiy Island, located close to the shore, is the largest island in the Kandalaksha Gulf. The White Sea is a water-filled depression in the block of a continental shelf known as the Baltic Shield. Its bottom is very uneven and contains the Kandalaksha Hollow in the northwest and the Solovetsky Islands in the south. Also, the Onega Bay has many small underwater elevations. The opening
Lake Onega area containing the Kondopozhskaya (, depth up to ), Ilem-Gorskaya (), Lizhemskoy () and Unitskoy () bays. To the southwest of Greater Onega lies Petrozavodskoye Onego () containing the large Petrozavodsk and small Yalguba and Pinguba bays. To the east of Zaonezhye there is a bay, northern part of which is called Povenetsky Bay and the southern part is Zaonezhsky Bay. There, deep sections alternate with banks and islands which split the bay into several parts. The southernmost part of them, Lesser Onega, is deep. All the shores there are rocky. The average depth of the lake is , and