Berlin Olympic Park is a large, well-preserved site from the 1936 Summer Olympics which were held in Berlin. It’s a good spot to enjoy a scenic and historic run around the stadium and the Olympiapark grounds containing numerous fields and other recreational facilities. Overall, it’s 3-4 km. For longer, extend into the adjacent Mahnmal Ehemalige (Memorial Park), which has ~3 km of paths, with a running track at the far northern end. To the north, you could add Ruhwald Park, or combine this run with our Grunewald Forst route.