Valaam Monastery built
1407 CE.
Shown on the map at 61.389°, 30.944°.
The Valaam Monastery (Russian: Валаамский монастырь; Finnish: Valamon luostari) is a stauropegic Orthodox monastery in Russian Karelia, located on Valaam, the largest island in Lake Ladoga, the largest lake in Europe.
Text from the Wikipedia article Valaam Monastery, licensed CC BY-SA 4.0.