The Heiligenberg is a wooded hill overlooking the town of Heidelberg in Baden-Württemberg, Germany. It rises to around 440 metres and has been the site of several historical buildings: a Celtic hilltop fortification, a Roman sacred precinct, several mediaeval monasteries, modern lookout towers and a Thingstätte, built by the Nazis in the 1930s. The latter is a rather chilling place, despite a hot, sunny day with lots of tourists and dogwalkers.
During the Third Reich, the Heidelberg Thingstätte open-air theatre was constructed in 1934/5 on the ridge between the Heiligenberg and the Michaelsberg as part of the Thingspiel movement. It is one of four hundred such venues planned, but only forty built. Today, it is once more in use as a venue for open-air events.