Saimaa Canal in the context of "Bay of Vyborg"

Vyborg (/ˈviːbɔːrɡ, ˈviːbərk/; Russian: Выборг, IPA: [ˈvɨbərk]; Finnish: Viipuri, IPA: [ˈʋiːpuri]; Swedish: Viborg, IPA: [ˈvǐːbɔrj] ) is a town and the administrative center of Vyborgsky District in Leningrad Oblast, Russia. It lies on the Karelian Isthmus near the head of Vyborg Bay, 130 km (81 miles) northwest of St. Petersburg, 245 km (152 miles) east of the Finnish capital Helsinki, and 38 km (24 miles) south of Russia's border with Finland, where the Saimaa Canal enters the Gulf of Finland. The most recent census population of Vyborg is 72,530 (2021 census).

Vyborg was founded as a medieval fortress in Finland under Swedish rule during the Third Swedish Crusade. After numerous wars between the Russians and Swedes, the Treaty of Nöteborg in 1323 defined the border of eastern Finland, and would separate the two cultures. Vyborg remained under Swedish rule until it was captured by the Russians during the Great Northern War. Under Russian rule, Vyborg was the seat of Vyborg Governorate until it was incorporated into the newly established Grand Duchy of Finland, an autonomous part of the Russian Empire. Finland declared its independence from Russia in 1917, after which Vyborg became its second-most significant city after Helsinki, and represented internationally as its most multicultural city. During World War II, Vyborg's population was evacuated and the town was ceded to the Soviet Union. In 2010, Vyborg was conferred the status of "City of Military Glory" by Russian president Dmitry Medvedev.

Salpausselkä (Finnish: [ˈsɑlpɑu̯sˌselkæ]; "Bar Ridge") is an extensive ridge system left by the ice age in Southern Finland. It is a large terminal moraine formation that formed in front of the Baltic ice lake during the Younger Dryas period about 12,250–10,400 years ago. All together the formation is close to 500 km (310 mi) from end to end, and the ridges can be as tall as 80 m (260 ft) in some places.

It runs from Hanko hundreds of kilometers to the east. It traps the extensive river and lake systems of Central Finland known as Finnish Lakeland (Finnish: Järvi-Suomi, "Lake Finland") and forces the water to flow through few breaches in the ridge. The Vuoksi River flows from lake Saimaa into Lake Ladoga (Finnish: Laatokka) in Russia. From there the water subsequently flows through river Neva into the Gulf of Finland, bypassing the Salpausselkä. The Kymi River flows from Päijänne into the Gulf of Finland. An artificial breach from the Lakeland is the Saimaa Canal, from Saimaa at Lappeenranta into the Gulf of Finland at Vyborg.

The Port of Lappeenranta (Finnish: Lappeenrannan satama, Swedish: Villmanstrands hamn) is an inland harbour in the city of Lappeenranta, Finland, on the southern shore of Lake Saimaa. It is located in the city centre on the Kaupunginlahti bay, and is therefore also known as the Kaupunginlahti harbour.

Scheduled international passenger services run from Lappeenranta to the Russian city of Vyborg (Finnish: Viipuri) on the Gulf of Finland, and wider afield, via the Saimaa Canal, which starts some 6.5 kilometres (4.0 mi; 3.5 nmi) east of the harbour. The total number of international passengers (departures and arrivals) was c. 16,400 in 2018.