Concealed behind a red door lies the historic air raid shelter where countless valuable works of art (e.g. the imperial regalia, Albrecht Dürers engravings, Martin Behaims globe, the Annunciation of Veit Stoss and the Männleinlaufen) survived World War II unscathed.
By early 1940, the first climate-controlled cells were ready for use. The rock-cut sandstone cellars themselves go back in part to the late 14th century and lie up to 24 m deep beneath the castle hill.
The story of the WW II art bunker is told in the exhibition "BombenSicher Der geheime Kunstbunker im Burgberg". Tours daily.