The castle complex, acquired in 1621 by the Thun und Hohenstein family, is a prominent landmark in the town's recently restored historic urban conservation area.
The castle is set in an extensive landscape park, with 220 tree species, some rare from around the world.
The park features a Baroque style sala terrena pavilion, with a gloriette mezzanine decorated with architectural sculptures by Jan Brokoff (1680s).
The park's northern section has an installation of the Stations of the Cross (1690s) and the Church of the Holy Trinity with the Crypt of the Thun noble family.
The Klášterec nad Ohří Castle exhibits in the Porcelain museum of Klášterec nad Ohří an extensive porcelain collection from the Museum of Decorative Arts in Prague.