Kadaň Castle was founded around 1260 during the reign of King Přemysl Otakar II. A strategically important site on a rocky outcrop overlooking the Ohře River was chosen for its construction.
One of the castle's distinctive features is its location at the edge of the town's fortifications rather than in the centre. Defensive walls extend from the castle in two directions, enclosing the entire historic town centre. The castle was also fortified on the side facing the town, allowing it to serve as a final stronghold if the town itself was captured.
Originally built in the Early Gothic style, Kadaň Castle looked very different from the structure we see today. It belonged to a type of Central European castle characterised by a square layout with towers at each corner.
During the 16th century, the castle underwent extensive Late Gothic and Renaissance renovations. However, it suffered devastating damage during the Thirty Years' War (1618–1648), when Swedish troops besieged Kadaň. The castle was looted, set on fire and subsequently fell into ruin.
Its restoration did not begin until after 1750, when it was repaired and converted into military barracks as part of the reforms introduced by Empress Maria Theresa. Although these changes saved the building from further deterioration, they also significantly altered its original medieval character.
Today, visitors can explore a museum exhibition dedicated to the history of Kadaň Castle, housed in its preserved Gothic cellars.
Other parts of the castle complex are home to the Kadaň Municipal Library and a residential care home for senior citizens.