Femöre Coastal Artillery Battery, Cold War military museum in Oxelösund, Sweden.

Femöre Coastal Artillery Battery is a military museum in Oxelösund Municipality, Sweden, built into the bedrock along the coast. The site consists of tunnels dug through solid granite that connect a series of underground rooms, including command posts and crew quarters.

Construction began in 1961, the first gun was ready in 1963 and the whole facility was completed in 1964. It was the third of 30 Cold War forts built along the Swedish coast as Battery OD, defending against attack from the Soviet Union. The last exercise took place in 1994, the guns were last test-fired in 1990, and the fort left the war organisation in 1997. A local association formed in 2004 saved it from demolition and opened it as a museum.

The name Femörefortet comes from the Femöre peninsula, and the facility was known in the military as Battery OD. The 70-man crew included 10 officers and 60 enlisted men, and the fort held a command centre, crew quarters, kitchen, workshops and a sick bay. Two decoy guns and a decoy radar were part of its wartime organisation.

Guided tours run mainly during summer, and group visits can be arranged in advance throughout the year. The underground sections are cool and damp, so bring a light jacket and wear shoes with a good grip.

The bunker was designed to house up to 70 people and could operate completely on its own, with independent power generators and communication systems. This meant the crew could keep the installation running for an extended period without any outside support, even if the surrounding area was under attack.