Map - Bohinj

Bohinj (Wochein), or the Bohinj Valley (Bohinjska dolina) or Bohinj Basin (Bohinjska kotlina), is a 20 km long and 5 km wide basin in the Julian Alps, in the Upper Carniola region of northwestern Slovenia. It is traversed by the Sava Bohinjka river. Its main feature is the periglacial Lake Bohinj (Bohinjsko jezero). Bohinj is part of the Municipality of Bohinj, the seat of which is Bohinjska Bistrica.

The basin consists of four geographic units: the Lower Valley (Spodnja dolina), Upper Valley (Zgornja dolina), Ukanc Basin or Lake Basin (Ukanška kotlina; Jezerska kotlina), and Nomenj Basin (Nomenjska kotlina). It is bounded by the Komarča head wall on one end and Soteska Canyon at the other. The Lower Bohinj Mountain Range represents its southern border. The Sava River has carved a canyon between the Jelovica and Pokljuka plateaus in the east. To the north, Mount Triglav, Slovenia's highest mountain, is also a part of the municipality.

The Sava Bohinjka (which merges with the Sava Dolinka into the Sava) begins when two rivers, the Jezernica and the Mostnica, merge. The Mostnica comes from the Voje Valley, whereas the Jezernica is a very short river that flows from Lake Bohinj. Many smaller streams flow into the lake. The largest of them, the Savica, emerges in Komarča as a large waterfall. Savica Falls (Slap Savica) gets most of its water from Black Lake (Črno jezero), which is the largest in the Triglav Lakes Valley (Dolina Triglavskih jezer).