The Reka, also the Inner Carniola Reka, is a river that starts as Big Creek in Croatia, on the southern side of Mount Snežnik, and flows through western Slovenia, where it is also initially known as Big Creek. The river is 54 km (34 mi) long, of which 51 km (32 mi) is in Slovenia. At the village of Škocjan it disappears underground through Škocjan Caves, flowing 38 km (24 mi) underneath the Slovenian Karst. The river continues as part of the Timavo in Italy. Tracer studies have shown that it also feeds springs elsewhere on the Adriatic Coast between Trieste and Monfalcone. It has a pluvial regime.