Germans love swimming pools. There are lots of fun indoor pools all across the country usually with lots of things for kids. There will be loads in Berlin, but probably bigger and better ones in the suburbs.

There are also lots of unique outdoor playgrounds for kids with ingenious activities, if the weather is good.

Watch out for hotel hottubs and spas, though, if you don't want to be answering lots of questions. Many are all nude.

There is a small Legoland center, which is kind of fun but expensive. There are lots of great parks. What time of year and where are you staying?

If you can make it down to Zirndorf (about 4 hours away by Nurenburg), there is a Playmobil Fun Park. Best place ever for kids!!!

The reichstag should be fun for a 4 year old.

Look up Tripadvisor.com many threads, and good advices.

The zoo, the food hall at KaDeWe, pigeon-chasing in one of the bigger parks. Simply riding the S-bahn or U-bahn would probably be a thrill.

Good luck. I did not find Germany to be a very child-friendly country. Maybe Berlin will be better though...

THis will be our DS' first time flying across Atlantic. We will be staying in Berlin. Can anyone recommend fun stuff to do with a four year old? I am afraid I can't take him on a Holocaust related tour or to portrait museums, he's not that big into art