Lake Onega of Petrozavodsk–Kizhi, Petrozavodsk–Velikaya Guba and Petrozavodsk–Shala. They are run by hydrofoil and motor ships and are used for passenger transport as well. In addition, passenger ships go on the route Petrozavodsk – Shala. Sailing is a popular activity on the lake and there is a sailing club in Petrozavodsk. Since 1972, every year at the end of July the lake has hosted the largest regatta in Russia ("") which is the Russian Open Championship in the Russian class of Cruisers Yachts "Open800". The regatta has international status. The largest city on the lake is Petrozavodsk – the capital of Republic
Lake Onega the last Ice Age, about 12,000 years ago: In the Paleozoic Era (400–300 million years ago) the entire territory of the modern basin of the lake was covered with a shelf sea lying near the ancient, near-equatoric Baltic continent. Sediments at that time – sandstone, sand, clay and limestone – form a layer covering the Baltic Shield which consists of granite, gneiss and greenstone. The retreat of the Ice Age glaciers formed the Littorina Sea. Its level was first higher than at present, but it gradually lowered, thereby decreasing the sea area and forming several lakes in the Baltic region.