Karlštejn Castle was built by Charles IV in 1348 to guard the crown jewels, and unlike its counterpart in Prague, this sucker’s actually a full-on castle. We’re talking a big-ass wall perched on a mountain top and pawning the cutest little support town you’ve ever seen, now mostly desperate souvenir shops. The schlep there and back can be done in half a day, and the images of the Czech countryside, run-ins with priceless locals, and the self esteem boost you’ll get from imagining you own it all will be some of the most memorable parts of your trip. If you’re even thinking of going, make a reservation now for the second, extended tour (available May-Oct), which takes guests into the heart of the castle including the Chapel of the Sacred Heart and some incredible medieval ruins. Those lucky enough to get a reservation can sleep easy knowing they’ve seen one of the top three sightsin the entire Czech Republic. Travelers in less of a hurry can stay over for lunch or take a hike through the woods, which are jurassically overgrown and green in the summer.