May is a great time of year in Denmark.
There are some obvious tourist attractions, such as Tivoli, Zoologisk have, Havnerundfart and Dyrehavsbakken, but my best recommendations would be:
- The Open Air Museum (www.frilandsmuseet.dk
- The Viking Ship Museum (www.vikingeskibsmuseet.dk
- The medieval centre (www.middelaldercentret.dk
A trip in a rented canoe down mølleåen is great fun.
A visit to Jægersborg Dyrehave, Zoologisk Museum, Danmarks Akvarium or Planetariet is also recommendable.
There is an inspirational site about children activities in Denmark, but unfortunately it is in danish: www.sjovforborn.dk