One of my favourite places in Berlin is the skatepark located in a far corner of historic Templehof airport. Templelhof was once the largest building in the world and was the main airport during the Berlin Airlift when the Soviets cut off all land access for the Allied forces into West Berlin. Templehof stopped operating as an airport in 2008 and the huge space is now used by Berliners for picnics, bike riding, gardening, jogging, kite flying and countless other sporting activities.
The small street style skatepark is built from granite slabs taken from the Palace of the Republic, the old GDR parliament which was demolished in 2008. There is something great about so many layers of intense history being used for a hedonistic activity like skating.