The Reka (literally, 'river' in Slovene), also the Inner Carniola Reka (Slovene: Notranjska Reka), is a river that starts as Big Creek (Croatian: Vela voda) in Croatia, on the southern side of Mount Snežnik, and flows through western Slovenia, where it is also initially known as Big Creek (Velika voda). The river is 54 kilometres (34 mi) long, of which 51 km in Slovenia. At the village of Škocjan it disappears underground through Škocjan Caves (a UNESCO World Heritage Site), flowing 38 km (24 mi) underneath the Slovenian Karst. The river continues as part of the Timavo in Italy, however, tracer studies have shown that it also feeds springs elsewhere on the Adriatic Coast between Trieste and Monfalcone. It has the pluvial regime.