There are five fish ponds by the banks of the Ljubljanica, formed from abandoned clay-pits dug for the former Kotnik brick factory. Today the ponds are home to many species of birds, fish, some rare bivalves, freshwater crabs and marsh tortoise. The fish ponds are managed by the Angling society of Vrhnika. Close to the site of the fish ponds, in Verd, during an archaeological excavation of the Ljubljanica river bed, a yew spear was discovered. Subsequent dating of the Spear put its age of manufacture in the Old Stone-age (38.000 – 45.000 years ago). According to current information it is the only such find in the world.