The ruins of the castle Kačnik or Kačji Grad are still impressive enough to easily be seen on the hill in Lokovina. They evoke many guesses in us, especially about what the castle looked like during its days of might. The experts put their trust in the search for the original estate at the nearby Ranšperk castle, which was testified to in 1208, but mentioned in 1335 as the “old house”, which means that a new castle was built in its vicinity.

This was first mentioned in 1275, and already in 1346, Eberhard Dobrnski pawned his castle Dobrna to the Krško Cathedral Chapter for  120 Aquiley Pounds, and later it found itself in possession of the Ptuj lords. In 1613, the land was sold to Gačnik family. In 1666 Emperor Leopold I. raised the then owner of Dobrna, Janez Matija Gačnik, to nobility with the predicate von und zu Schlangenberg auf Schlangenburg; from here comes the Slovenian word for the name of the castle – Kačji Grad. In 1769, Franc Ksaver Avgustin Baron of Dienersberg bought the castle building, but in only three years, he had to leave it at night, together with his family and servants, because the castle began to collapse. The Dienersberg set up a new mansion in the valley two years later, which inherited the name of the old castle.