There's more than one Torture Museum in Prague. And when you do go, please go and see soem other parts of CZ. It is a wondrful, amazing country.

So, anyway, I only get to pick one? This is tough.

The Silk Road has to top the list
Karakoram Highway by bicycle (as if I'd ever be hardcore enough for that!)
Galapagos Islands
Skiing in the Balkans, particularly in a landmine-free Sarajevo (but that would be yeeeears off )