The ruins of the defensive castle, the area of which covers almost 8 hectares, which makes them one of the most extensive castle ruins in Slovakia and even in Europe. The castle is also known as the Old Zvolen Castle.
The chronicles show that the first stronghold existed in this place already at the turn of the 9th and 10th centuries. The oldest castle, the so-called The upper one dates back to the 12th century. It consisted of a stone tower surrounded by a moat. In the 13th century, a great expansion of the castle took place, which became a military and administrative center of the so-called the state of Zwoleń, i.e. areas covering all of today's central Slovakia. A borough and the so-called Lower Castle, which defended access to the Upper Castle. When the stronghold in Zwoleń was built at the end of the 14th century, the castle began to lose its significance. In 1451 it was looted and burned and quickly fell into ruin.
An interesting fact is that the area where the castle was built was already inhabited in the Copper Age. In the Bronze Age, the people of the Lusatian culture built stone fortifications here, which partly coincide with the walls of the Empty Castle.