Izvorul Bigăr (English: Bigar Spring, but more commonly known as Bigar Spring) is a protected area (nature reserve IUCN category IV) situated in the administrative territory of Bozovici, in Caraş-Severin County in southwestern Romania. The Izvorul Bigăr is located at the south-west limit of the country, in the south of the Anina Mountains (a group of mountains included in the Banat Mountains), in Caraș-Severin County, on the upper Anina River, in the Cheile Nerei-Beușnița National Park.
Izbucul Bigăr with an area of 175.60 ha was declared a natural protected area by the Law Number.5 of March 6, 2000 (published in Romanian Official Paper Number.152 in April 12, 2000). Bigăr is one of the most unusual waterfalls in the world and one of the most beautiful in Romania. According to The World Geography, there are a number of facts that place her as number one on the list of eight unique waterfalls around the world due to the way the water spreads and falls in tiny shreds of water, and also the fact that it is located exactly on the 45th parallel north, at the halfway point between the Equator and the North Pole.