Visiting Berlin is challenging in terms of picking activities since you have so many cool places to chose between fitting your interrailing checklist. Although, one that we find as a really good option is the former airport Tempelhof which nowadays functions as a public park. The airport itself closed down year 2008 and has a eventful history being for example the most important airport for the Nazis during Second World War. Today the field is a perfect spot for relaxing, barbequing or inline skating, doing all this at an old airport creates a unique atmosphere. Aaand, best of all, for free of course!