Fun things in the Madison area for visiting tourists???

[red5_standingby]

My sister and nephew (11) are visiting from out of town.  Looking for some suggestions for things to do with them tomorrow.  Here's some things I've thought of so far, anyone have any more I can consider???

1) Ella's Deli (Lunch and carousel)
2) Zoo
3) Cave of the Mounds
4) House on the Rock
5) Dr. Evermores
6) Mustard Museum

Not looking to do all of them, just want to give them some choices.

Thanks.