The ruins of Přimda Castle stand on top of a rocky ridge above the town of the same name in the northern part of the Bohemian Forest. The first mention of Přimda dates back to 1121. The builder of the castle was probably the German Margrave Děpolt II of Vohburg, but from 1126 at the latest Přimda belonged to the Czech rulers as an important border fortress guarding the trade route from Prague and Plzeň to Horní Falce. In addition, it served as a royal prison where, among others, the later King Přemysl Otakar II was forced to stay. In the 15th and 16th centuries the castle was often pledged to noble families, especially to the Lords of Švamberk. The unmaintained castle fell into disrepair and by the 17th century it was an uninhabited ruin. A massive prismatic tower made of quarry stone and lined with granite blocks remains from the first half of the 12th century.