Tharandt Castle, as a distinctive ruin, shapes the historic image of the town of Tharandt near Freital in the district of Sächsische Schweiz-Osterzgebirge and stands on a spur of rock surrounded by the Schloitzbach and the Wilde Weißeritz. The ruin above and the immediately adjacent Schloss Tharandt together bear witness to the castle Romanticism of the 19th and 20th centuries, although only a few parts of the original fortifications have survived.
Built as a border defense after the neighboring Burg Thorun was destroyed in the early 13th century, the site is mentioned in written records of the region that, in 1294, link two neighboring installations. The castle served successive territorial rulers as a defensive and administrative center, endured sieges and fires in the 13th century, and was rebuilt in the mid-13th century. In the late Middle Ages a pledge to local comital families increased its importance as a strongly fortified seat of lordship and administrative office. Over time its military equipment was expanded; from the late 15th century residential alterations were made for ducal use, and the complex increasingly came to be referred to as a castle. After the death of the last duchess to reside here at the beginning of the 16th century, the castle fell into decay; building elements were removed and reused elsewhere, and later a large-scale demolition took place. On parts of the lower castle the town and mountain church was constructed between 1626 and 1629; it was consecrated in 1631 and has borne the name Zum Heiligen Kreuz since 1927. Around 1800 work began to secure the ruin in the spirit of castle Romanticism; numerous 19th-century artists recorded the view in paintings, including well-known painters and graphic artists such as Ludwig Richter, Caspar David Friedrich, Adrian Zingg and Carl Blechen. In the 20th century an open-air stage was laid out on the upper ward, and from 1976 archaeological investigations and restoration work in accordance with monument-preservation principles were prepared. From 2013 a comprehensive restoration of the ruin began; partnerships with Poděbrady (Podiebrad) and Cheb (Eger) connect it with European history. At town festivals medieval markets and public guided tours take place, which also include the church and the exposed cellar vaults; the church is open to visitors during the warm season.
Schloss Tharandt was built in the mid-19th century as a town palace in place of a country house and was later remodelled in a Moorish‑Oriental Tudor style. After a fire in the 1930s the building acquired its present appearance. For decades the Forstlehranstalt Tharandt used the palace; since the 2000s it has been in private ownership and is being renovated gradually. Both the castle ruin and Schloss Tharandt are registered as cultural monuments with the Saxony State Office for Monument Preservation.