Hamburg City Park / Hamburg

Hamburg is considered the greenest city in Europe!
While this entitlement could be discussed it's a matter of fact that Hamburg has some really nice green places to offer - one of them is the City Park (called "Stadtpark" in German) in the North of the Alster lake.
If you're exhausted after a long day or you don't feel like sightseeing all the time - go there! You will relax for sure! In summer many people are gathering there for BBQ, football, jogging, guitar singing, enjoying time outside in the nature.
At the pond in the middle of the parc you can even lend small boats and get along the canals of Hamburg! Check under "sightseeing" here on Raildude for other activities and for more info!
Easiest way to get to the parc is to take the subway, yellow line U3 until Borgweg (Stadtpark), when you leave the station turn left and go up the street for about 50m and then just follow the trees :)