Muskö naval base

Muskö Naval Base is a Swedish underground naval facility on the island of Muskö just south of Stockholm in Haninge Municipality (Haninge Kommun). The construction of the base started in 1950 and was completed 19 years later in 1969. During the construction about 1.5 million tons of rock were removed. It has 3 docks, originally designed for destroyers and submarines. The underground base itself has an area of several km² and is connected by 20 km (12 mi) of underground roads. A 3 km (1.9 mi) long, dangerously narrow road tunnel running some 70 metres (230 ft) under the sea level connects the mainland and Muskö island.

Muskö naval base

Muskö Naval Base is a Swedish underground naval facility on the island of Muskö just south of Stockholm in Haninge Municipality (Haninge Kommun). The construction of the base started in 1950 and was completed 19 years later in 1969. During the construction about 1.5 million tons of rock were removed. It has 3 docks, originally designed for destroyers and submarines. The underground base itself has an area of several km² and is connected by 20 km (12 mi) of underground roads. A 3 km (1.9 mi) long, dangerously narrow road tunnel running some 70 metres (230 ft) under the sea level connects the mainland and Muskö island.