Vertical sundial on the wall of mountain hut "Matija Filjak" on Hrastovička gora mountain, property of the Croatian Mountaineering Society "Zrin" from Petrinja. The sundial was built by Nenad Ćelap based on calculations by Slaven Ličina. The hut was made on the location of the old hut from the year 1938, which also had a sundial (link).