Non resort Holiday destinations

[Tantay]

Would love to hear some recommendations for holiday destinations/activities suitable for a family with a 4yo and a 10mo. Will be in June. Thinking Europe (not Spain or Portugal) especially Germany and Eastern Europe or east coast US. Just not sure how child friendly these places may be or if there is anything to do with the 4yo. Cheers!

We stayed in the area between Munich and Nuremberg and it was less than an hour's drive to either city.
In Munich we enjoyed what's supposed to be the best puppet theatre in Germany. There's a decent zoo called Hellabrunn. The English Garden is massive and is a nice place to enjoy ice cream, feeding the ducks and trip.

The Playmobil fun park is just outside Nuremberg. In the city itself there's an excellent hands-on children's museum, toy museum and transport museum. Tiergarten is a zoo with a good collection of animals, dolphin show, steam train and petting zoo. Playground of the Senses was good too.

If Playmobil isn't enough, Legoland was only an hour's drive away too.

Places we've visited with similar aged kids and loves:

Sweden
Verona
Innsbruck
Sicily
Copenhagen
The Hague

We're also planning trips to the luberon, Vienna and Geneva.