The Spreepark was closed in 2002, after running into enormous debts (and the owner was also since imprisoned for smuggling cocaine). Since then, most of the attractions still stand but with no upkeep, nature has engulfed the park, which is out of bounds to the public (albeit being secured by a very ricky metal fence, which is pretty easy to climb over).
Despite a 5am start, breaking into the abandoned theme park was completely worth it. The photos probably don't do it justice as we had to move quite quickly through fear of being caught by the guards, but it was such an eerily beautifully place, something almost post-apocalypic about the atmosphere.
We visited the park between 6- 7am on a weekday morning — although there are no guarantees if you are going then this seems like a pretty good time as it was quiet on the perimeter so no one saw us climb the fence and if there were guards on duty then they must have still been half asleep because we were there for about 40 minutes without hearing a peep.