Karlštejn Castle, a large Gothic castle founded in 1348 by Charles IV, is one of the most impressive and visited castles in the Czech Republic. It's advisable to book tours in advance, especially during peak season (summer), as entry is often timed and guided tours are the norm. While solo exploration is possible in some areas, the most significant parts of the castle, like the Chapel of the Holy Cross, are accessible only with a guided tour. Accessibility can be challenging due to the castle's hilltop location and numerous stairs. Expect a visit to last between 2 to 4 hours, and the approximate cost for tours ranges from 200 to 500 CZK depending on the chosen circuit. Note that photography restrictions may apply in certain areas.