If you want authentic medieval castle experience without Prague Castle's tourist circus, take the train to Karlštejn. Only 40km southwest with hourly trains from Hlavní nádraží station.

Castle perched dramatically on hilltop, built by Holy Roman Emperor Charles IV to house crown jewels. Guided tours are actually good here — Imperial Palace and Chapel of the Holy Cross with precious stones and medieval paintings if you book ahead.

Village below has decent restaurants. Total trip 4-5 hours including travel, perfect half-day escape from city crowds.