It may have a terrifying name, but at 115m high, the Teufelsberg (Devil’s Mountain), just south of the Olympic grounds, ain’t no Matterhorn. It is, however, the tallest of Berlin’s 20 ‘rubble mountains’, built by citizens, initially most of them women, during the clean-up of their bomb-ravaged city after WWII. It took 20 years to pile up 25 million cubic metres of debris. The curious domed structure up on top used to be a listening station operated by the Allies during the Cold War. The hill that was born from destruction is now a fun zone, especially in snowy winters when hordes of squealing kids toboggan or ski down its gentle slopes. At other times you can explore the terrain on mountain bikes or watch colourful kites flutter like swarms of butterflies. The little Teufelssee lake at the bottom of the hill is popular with nudists (especially the south shore). On its eastern shore is the Ökowerk , a nature conservation and education centre that’s grown up around Berlin’s oldest existing water works (1872). Learn about water and its role in our lives in an interactive exhibit, then romp around various themed gardens and ponds.