Vyborg Castle, Medieval castle in Vyborg, Russia

Vyborg Castle is a medieval fortress built on a small island in the city of Vyborg, in northwestern Russia, with the tall Saint Olaf Tower as its most visible feature. The main structure has a four-sided layout surrounded by walls, additional towers, and open courtyards.

The fortress was founded in 1293 by Swedish marshal Torkel Knutsson during a military campaign into Karelian territory. Over the following centuries it passed between Swedish, Russian, and Finnish control before becoming part of Russia again in 1944.

The castle is a gathering point for visitors curious about the history shared between Sweden, Finland, and Russia in this part of Karelia. Inside the tower, a viewing platform gives a wide look over the old city and the bay below.

The castle is reached by a short bridge from the city shore, making it easy to walk to on foot. The ground inside is uneven in places, so sturdy footwear helps when exploring the courtyards and climbing the tower.

During a 1495 siege, an unexplained explosion on Saint Andrew's Day stopped a Russian attack and became known as the Vyborg Blast. No one has been able to determine exactly what caused it, and accounts from the time offer no clear answer.