The ruins of a medieval castle situated on a phonolite crag (elevation 717 m) are a dominant landmark near the road leading from Karlovy Vary to Prague. At first it was mentioned in 1402 in a written account by Boreš from Osek. During its existence, the castle changed hands frequently – alternately, it belonged to the lords of Hasenburg, to the Vřesovice family, the Schlick family, to the lords of Plauen, the Czernin family and to the royal crown as well.
The oldest part of the castle is a four-sided residential tower, which is visible from a distance and which was most likely built during the time of the Schlick family. At the turn of the 15th and 16th centuries, Andělská Hora was the seat of the Plauen estate and the castle underwent an extensive reconstruction and expansion. In the mid-16th century, a two-storey Renaissance palace was built with an unusual pentagon-shaped layout due to the configuration of the terrain. After being captured by the Swedish in 1635, the castle was maintained merely out of necessity and abandoned once and for all after a fire in 1718.
Andělská Hora was a popular picnic spot with the spa guests of Karlovy Vary during its greatest boom. In 1786, it was even visited by Johann Wolfgang Goethe. The craggy hill rises 100 m above the environs and, in clear weather, provides a fantastic view that stretches far beyond the boundary of the geopark – to the eastern region of the Krušné Hory Mts., to the volcanic Doupovské Hory Mts. and even as far as the Teplá and Slavkovský les Highlands.
From the geological perspective, it is a Tertiary chimney in the western front zone of the Doupov Volcanic Complex, which broke through the granites of the Karlovy Vary Pluton and was later exposed by denudation above the level of the surrounding planated surface. It consists of phonolite, a compact olive grey volcanic rock with an almost greasy lustre and visible minute columnar crystals of glassy sanidine and black pyroxene.
The former Pilgrimage and Cemetery Church of the Holiest Trinity from 1712, a valuable religious monument, is located in the town below the castle. Its unique feature is an entirely regular triangular layout. Near the church stands a historic lime tree, where a spring once flowed, whose water is said to have miraculously cured numerous sick pilgrims.
A nature trail that passes through Andělská Hora leads us further on to Šemnická Cliff, which is linked to old legends. Another interesting route leads along a local trail dedicated to the history of Andělská Hora.