The Neva is the only river flowing from Lake Ladoga. It flows through the city of Saint Petersburg, three smaller towns of Shlisselburg, Kirovsk and Otradnoye, and dozens of settlements. The river is navigable throughout and is part of the Volga–Baltic Waterway and White Sea – Baltic Canal. It is a site of numerous major historical events, including the Battle of the Neva in 1240 which gave Alexander Nevsky his name, the founding of Saint Petersburg in 1703, and the Siege of Leningrad by the German army during World War II.
There are at least three versions of the origin of the name Neva: from the ancient Finnish name of Lake Ladoga (Finnish: nevo meaning sea), from the Finnish: neva (short from Finnish: Nevajoki, Nevajärvi) meaning swamp, or from the Swedish: ny – new river. Modern names for the distributaries of the river delta were settled only by the end of the 18th century.
In the Paleozoic, 300–400 million years ago, the entire territory of the modern delta of the Neva River was covered by a sea. Modern relief was formed as a result of glacier activity. Its retreat formed the Littorina Sea, the water level of which was some 7 to 9 metres (23 to 30 ft) higher than the present level of the Baltic Sea. Then, the Tosna River was flowing in the modern bed of the Neva, from east to west into the Litorinal Sea. In the north of the Karelian Isthmus, the Littorina Sea united by a wide strait with Lake Ladoga. The Mga River then flowed to the east, into Lake Ladoga, near the modern source of the Neva River; the Mga then was separated from the basin of the Tosna.
Near the modern Lake Ladoga, land rose faster, and a closed reservoir was formed. Its water level began to rise, eventually flooded the valley of Mga and broke into the valley of the river Tosna. The Ivanovo rapids of the modern Neva were created in the breakthrough area. So about 2000 BC the Neva was created with its tributaries Tosna and Mga. According to some newer data, it happened at 1410–1250 BC making the Neva a rather young river. The valley of Neva is formed by glacial and post-glacial sediments and it did not change much over the past 2500 years. The delta of Neva was formed at that time, which is actually pseudodelta, as it was formed not by accumulation of river material but by plunging into the past sediments.
The Neva flows out of Lake Ladoga near Shlisselburg, flows through the Neva Lowland and discharges into the Baltic Sea in the Gulf of Finland. It has a length of 74 kilometres (46 mi), and the shortest distance from the source to the mouth is 45 kilometres (28 mi). The river banks are low and steep, on average about 3 to 6 metres (10 to 20 ft) and 2 to 3 metres (7 to 10 ft) at the mouth. There are three sharp turns: the Ivanovskye rapids, at Nevsky Forest Park of the Ust-Slavyanka region (the so-called crooked knee) and near the Smolny Institute, below the mouth of the river Ohta. The river declines 4.27 metres (14.0 ft) in elevation between source and mouth. At one point the river crosses a moraine ridge and forms the Ivanovskye rapids. There, at the beginning of the rapids, is the narrowest part of the river: 210 metres (690 ft). The average flow rate in the rapids is about 0.8–1.1 metres per second (2.6–3.6 ft/s). The average width along the river is 400 to 600 metres (1,300 to 2,000 ft). The widest places, at 1,000 to 1,250 metres (3,280 to 4,100 ft), are in the delta, near the gates of the marine trading port, at the end of the Ivanovskye rapids near the confluence of the river Tosna, and near the island Fabrinchny near the source. The average depth is 8 to 11 metres (26 to 36 ft); the maximum of 24 metres (79 ft) is reached above the Liteyny Bridge, and the minimum of 4.0 to 4.5 metres (13 to 15 ft) is in Ivanovskye rapids.