In addition to the fabulous medieval castle
This area offers some great hiking opportunities in the surrounding bohemian karst forest.
We took the train from Prague central station to Karlstejn, the journey takes about 40 minutes. From the station it is a two kilometer climb up to the castle through a wide range of tourist oriented facilities. If you don't want to walk you could go by horse and carriage.
You need to take a tour to go into the castle we took the basic 50 minutes tour, for the longer tours you need to book in advance. The castle was built by Charles IV, the holy roman emperor who put Prague on the map. Charles was an interesting man he was educated in France, had four wives and was considered to be extraordinarily hygienic as he washed four times a month.