Stari Grad Veliki Kalnik, Medieval castle ruins in Kalnik, Croatia

Stari Grad Veliki Kalnik is a stone castle ruin situated on a hilltop in the Kalnik region. The site preserves sections of original walls and defensive structures that reveal how medieval fortifications were built and arranged.

The fortress was built in the 12th century and became strategically important during the Mongol invasion of 1243. It was one of several defensive positions that helped protect the region during this period of threat.

Local tradition links the fortress to the šljivari, plum growers who, according to legend, fed King Béla IV and his retinue plums while they hid from the Tatars; the king rewarded them with noble titles. The story inspired Šenoa's work "Šljivari" and Milutin Mayer's novel "Tatari u Hrvatskoj". A memorial plaque near the castle marks the Croatian victory over the Tatars.

The ruins stand on the Sveta Katalina hill above the village of Kalnik, reached on foot by marked trails; hikers and excursionists climb up especially on 1 May. The ground among the walls is uneven, so wear sturdy footwear, and carry water because the hilltop offers no facilities. The surviving walls are those of the rectangular keep and the 17th-century castle below it.

The ruins display traces of building styles from different periods, as the fortress was altered and expanded over centuries. Visitors can still see which sections were added or modified during different eras.