Named after the hill carved in between old and new Trzin, the Onger Mountaineering Association (Planinsko drštvo Onger in Slovene) was founded in 1983 and has worked tirelessly ever since helping Trzin’s drive towards ecology. Specifically aimed towards the people of Trzin before it even gained municipal independence, they would organize tours to attract new members as well as focusing explicitly on young mountaineers. Their legacy can be felt in the 1.2km long Onger Trail, traversing the hill of the same name and full to the brim with trees and plants of differing shapes, sizes and prevalence. A handy guide to each plant of interest can be found at the beginning of the trail, all be it in Slovene only. The highest point of the trail is 377m. For more information, contact the Mountaineering Association.