The Plyussa is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in Pskov Oblast

Pskov Oblast

Pskov Oblast is a federal subject of Russia . Pskov Oblast borders the countries of Estonia and Latvia, as well as Belarus. It is the westernmost federal subject of contiguous Russia . Its major cities are the administrative center Pskov and Velikiye Luki . Area: 55,300 km²...

 and Leningrad Oblast

Leningrad Oblast

Leningrad Oblast is a federal subject of Russia . It was established on August 1, 1927, although it was not until 1946 that the oblast's borders had been mostly settled in their present position...

 of Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, a right tributary of the Narva

Narva River

The Narva is a river flowing into the Baltic Sea, the largest river in Estonia. Draining Lake Peipsi, the river forms the border of Estonia and Russia and flows through the towns of Narva/Ivangorod and Narva-Jõesuu into Narva Bay. Though the river is only 77 km long, in terms of volume...

. It joins the Narva at the southern bay of the Narva Reservoir

Narva Reservoir

Narva Reservoir is a reservoir by Narva River, shared by Russia and Estonia.The reservoir was constructed during 1955-1956, during the Soviet times. It provides water to Narva Hydroelectric Station and cooling water to the Estonian Narva Power Plants...

. The town of Slantsy

Slantsy

Slantsy is a town and the administrative center of Slantsevsky District of Leningrad Oblast, Russia, situated on the Plyussa River, west of St. Petersburg. Population: ....

 and a settlement of Plyussa

Plyussa

Plyussa is an urban locality and the administrative center of Plyussky District of Pskov Oblast, Russia, located northeast of Pskov by the Plyussa River. Population:...

 are situated upon the Plyussa.

Plyussa is 281 km long, the river basin area is 6550 km².

The river lent its name to the Treaty of Plyussa, concluded at its banks, which ended the Livonian War

Livonian War

The Livonian War was fought for control of Old Livonia in the territory of present-day Estonia and Latvia when the Tsardom of Russia faced a varying coalition of Denmark–Norway, the Kingdom of Sweden, the Union of the Grand Duchy of Lithuania and the Kingdom of Poland.During the period 1558–1578,...

between Sweden and Russia in 1583.