Hanko Naval Base

The Soviet Union had demanded from Finland a military base in the writing of regional exchange requirements just before outbreak of the Winter War from Hanko peninsula.

[1] After the Winter War, in the early Spring of 1940, the Soviet Union repeated its call for a naval base in the Hanko area.

Finland's negotiation delegation was forced to agree to the Soviet Union's peace terms, including the Hanko base.

The Soviet Union fortified the border between Finland and the base, and the Finnish forces invested in troops and fortifications on their side.

The troops left their leased area heavily mined, which hampered the return of the civilian population in the Hanko peninsula.