Untertageanlage Lorch-Wispertal, Military underground facility in Lorch, Germany

Untertageanlage Lorch-Wispertal is an underground complex carved into the Ranselberg mountain to serve military storage needs. A main tunnel runs through the facility and connects to numerous chambers designed to accommodate large vehicles.

The facility was built in 1962 as part of military planning during the Cold War in West Germany. Its construction required extensive rock extraction and took more than 10 years to complete.

Lorch's council approved the Bundeswehr project on 11 May 1959, after the magistrates had already backed it, hoping a garrison would create local jobs. The depot was run by a full-time Bundeswehr fire brigade, and more than two thousand ionization smoke detectors were monitored from a fire station outside the mountain.

The facility is closed and not open to visitors, so there is no access to the tunnels. The two portals lie off the L 3033 from Lorch to Bad Schwalbach (entrance) and the L 3397 near Ransel (exit); the main tunnel runs about two kilometres through the Ranselberg, dropping steadily from Röderfell/Wolfsloch to the Tiefenbachtal. Trucks up to 3.30 m high and 4.00 m wide could pass.

The main tunnel descends continuously for about two kilometres from Röderfell/Wolfsloch to the Tiefenbachtal, and the whole complex lies tilted in the mountain, dropping 1% north to south and 1% east to west so that any water drains away.