A medieval fortress built in the middle of the 14th century on the prominent ridge of Cesarska gora above the Sutla valley and today's Klanjec.
According to tradition, the fortress of Cesargrad was built by the Templars, a knightly order founded in 1119 to protect pilgrims on their way to the tomb of Jesus in the Holy Land. On the opposite side, on the other side of the Sutla, at almost the same height of Bizeljska gora, is the rest of the Konigsberg fortress, or as the people of Klanje call it, Kunšperg, which is attributed to the same builders. The Order of the Templars was abolished in 1312, and their goods were assigned to other orders or became the property of the Crown.
Cesargrad (Kayersperg), on the prominent ridge of Cesarska gora, was first mentioned in 1399 in a gift from King Sigismund, with which he gave Cesargrad to Count Herman of Celje. As the last of the Celje deaths in Belgrade in 1456, Cesargrad came under the rule of the royal crown.
The medieval structure of the city consists of a semicircular stone building that had a residential function, surrounded by a system of walls, and a defensive tower. The fort was expanded and upgraded in several phases.
In 1573, Cesargrad was killed in the Peasant Revolt when it was looted and set on fire. The Erdody family partially restored it, but with the construction of the New Klanječki Palace (built by Ban Toma Bakač Erdody in 1603), the Erdody family slowly moved to the new castle, and the Cesargrad fortress was slowly falling into disrepair.