Just 13 kilometers from the center of Karlovy Vary is the quaint riverside community of Loket nad Ohri, where the prime tourist attraction is the splendid old castle perched high above the village. 

Built in the 12th century, Loket Castle (Hrad Loket) is remarkably well preserved and has endured with few alterations. 

Used as a prison from the 18th to the 20th centuries, the castle's thick stone walls earned it a reputation as the most impregnable fortress in Bohemia (the torture chambers offer a chilling look at the shocking treatment of enemies and prisoners).