Vela draga is the monument of exceptional geomorphologic value. It was created by water torrents which made a 3500 meter long canyon in limestone rocks. It starts at the Zrinščak tunnel and ends at the Boljunsko polje. It is special for its pointy rocks, with 50-90 meter tall towers, some of which were destroyed during the construction of the Učka tunnel. The highest part of the canyon is at 600 meters above the sea level, while the lowest is the one at the Boljunsko polje at the level of only 153 meters. The canyon is covered by lush vegetation ranging from willows and poplars to beech and jew. Some of it is the rainforest. Vela draga has been protected as a nature reserve and a geomorphologic monument of nature since 1963 and 1998, respectively. Apart from teaching about geological phenomena, this trail also teaches about alpine and free climbing, sports which have existed in Vela draga since 1931, when alpine climber Emilio Comici climbed his first alpine route. Vela draga has thus in time become a known climbing spot for acquiring precious experience by many Croatian and European alpine climbers.