See article here. We took a trip to the Eleven Park, a massive 4000 m2 play house in Buda. I had heard a lot of good things about it, and have seen that many international nursery schools take their kids there on occasion. For a deposit, you can have a locker, and everyone runs around in socks.

Transport between the games and rides for kids may be made on small trikes laying about. Among the things to do are trampolines, go carts, climbing walls, a huge wavy airbag, air hockey tables and a big airbag crocodile that eats the kids. The restaurant offers both Hungarian and international meals, including felafel, tortillas and big jugs of szorp. Its a lot of fun, but be prepared. It is noisy, and almost, but not quite pony-free!

Source: Treehugger Dan's Positive Blog