Salzbergwerks Salt Mines

For a different, but very entertaining tour good for people of any age, the Salzberwerks Salt Mine in Berchtesgaden, Germany is an excellent choice.  You'll be provided with overalls to go over your clothing to keep you warm during this tour into the depths of the salt mines.  To get there, you take a type of train that you ride on like a horse into the depths.  Afterwards, you explore the mines on foot led by an expert tour guide explaining to you everything you're seeing.  You'll also get to ride on a "slide" to get further into the mines, although there is the option to walk down.  We'd recommend the slide though is it is actually pretty fun.  The tour will last about an hour and you'll be entertained the entire time.

Beware that it can get very crowded here and everything is very time controlled, so if you don't want to have a long wait, plan to get here when they first open.