An unexpected discovery was made during conservation work at Vyborg Cathedral. The remains of two stone vaults were discovered under a layer of earth in the process of strengthening the foundations. Presumably in this place there was a side entrance to the choir.

The Cathedral began to be built in 1413, in 1554 it became the Cathedral. It was destroyed during the Great Patriotic War. Conservation work is now being carried out on the cathedral, which will allow the remaining part of the building to be preserved.