The Boka Waterfall is the highest waterfall in Slovenia, dropping 144 metres in a single vertical plunge into a deep gorge just south of Bovec. A short walk from the main Bovec-to-Trenta road leads to the viewpoint at the base of the falls. The spray and noise are formidable when the falls are running well; on a clear day a rainbow forms in the mist.
The falls can also be viewed from above — a longer walk leads up the Boka gorge to the point where the stream goes over the edge, and continues to the karst plateau where the springs emerge from the limestone. This is a serious half-day excursion requiring good footwear.