This large underground hangar was operated by the Swedish Air Force as a safe place to house the J29 Tunnans of no. 9 Wing, based at Save airfield. ; the deep excavated facility, 30 metres below the surface, was built during the cold war and became operational in 1955. Today the former top secret hangar houses the Aeroseum, a museum displaying all aspects of the Swedisch military aviation.
The displayed Alouette III (SE-JEI) is the former A-471 of the Dutch air force and the AB204 is the former 226 of the Dutch navy. Frank was in the museum in September 2022.