Not far from the village of Zlatno, on the wooded outcrop of the mountain of Tríbeč, there used to stand the Black Castle (orig. "Čierny hrad"), which protected mainly the sites of gold placer areas. Nowadays, only ruins, remains of masonry, outer ramparts and moat can be seen from this castle.

Black Castle belonged to Tekov County. Almost no records have been preserved from the history of the castle. Thanks to the archaeological research conducted in this area it is possible to assume its relatively short existence. It was built at the turn of the 13th and 14th century and disappeared somewhere at the turn of the 14th and 15th century.

Black Castle is a very pleasant place for easy hiking and relaxation in the lap of nature. Marked trail leads from the village Zlatno (about 3km). At first, it leads along the asphalt road and for the last 30 minutes, it is a bit more challenging as it is necessary to climb the hill by foot.