Berlin parks are never quite what they seem. Beneath the two large hills that dominate the landscape of the Volkspark are the remains of WWII bunkers that couldn't be destroyed. Berlin is a flat city. A simple rule of thumb could be, if you feel an incline and it's not a staircase, you're probably walking over a mountain of rubble. What's most interesting about the park, apart from the locals who use it - sometimes naked – are the stone monuments dropped around the park and the skateboarders who grind on them.