Heiligenberg is a 440-metre hill above Heidelberg, Germany, crowned by a Celtic hill fort [1]. The site later hosted a Roman sacred precinct and medieval monasteries [1]. Its summit also features the Nazi-era Heidelberg Thingstätte, an open-air theater built in the 1930s [1].
Heiligenberg, Heidelberg

| Type | Fortress/citadel |
|---|---|
| Period | 500 BC - 1 AD |
| Country | Germany |
| Coordinates | 49.4258° N, 8.7062° E |
Germany