Tiversk

thumb|right|The ruins of Tiversk.|231x231px Tiversk or Tiurinlinna (, ) is a site of ancient Karelian settlement and a ruined fortification near Melnikovo (Räisälä in Finnish) in the Karelian Isthmus. The fortification has been in use in different stages in history and it has also been described as a village. The site used to be an island of the River Vuoksi, which became a peninsula after 1857, near rapids. The island is approximately long and wide.

The oldest findings indicating settlement on the site are dated between 500BC–300AD. Several researchers have come to the conclusion that the site served as a fortification in the 11th century and possibly even earlier. Anatoly Kirpichnikov asserts that the fortification was founded in the late 1330s. Archaeologists have found stone foundations of 19 buildings which varied in size between and . There has also been one much larger building with a floor area of and a hearth in the middle of the building.