This clandestine hospital, hidden in a canyon near Dolenji Novaki, about 5km northeast of Cerkno, treated wounded Partisan soldiers from Yugoslavia and other countries from late 1943 until the end of WWII. A memorial to humanity and self-sacrifice, it had more than a dozen wooden cabins, including treatment huts, operating theatres, X-ray rooms and huts for convalescence. Nearly 600 wounded were treated here, and the mortality rate was only about 10%.
The complex, hidden in a ravine by a stream, had an abundance of fresh water, which was also used to power a hydroelectric generator. Local farmers and Partisan groups provided food, which was lowered down the steep cliffs by rope; medical supplies were diverted from hospitals in occupied areas or later air-dropped by the Allies. The hospital came under attack by the Germans twice but it was never taken.
There's another remarkable thing about the hospital: it was almost entirely destroyed by flood in 2007, and has been completely reconstructed. It's extremely well done; access is via a lovely 500m stream-side walking path.
