Martijn: Popular for weekend brunch. If you get there early you get to sit by the water.
Martijn: Wall Park? huh? Mauerpark this place is called. Great people watching and turns into a giant yard sale from time to time.
Martijn: Pick up some food and sit outside and people watch. Bergmannstraße is generally pretty pleasant.
Martijn: I'm pretty sure this is where I rented a bike when I was in Berlin for an extended stay. Price can't be beat and the folks are super friendly.
Colin: I haven't been there yet myself, but an overgrown amusement park sounds great. AFAIK there are guided tours.