Plura is a river in the municipality of Rana in Nordland county, Norway. The river begins at the lake Kallvatnet, flows through the Plurdalen valley, and ends up as a tributary to the river Ranelva, about 10 kilometres (6.2 mi) north of the town of Mo i Rana. The river is rich with salmon, trout, and Arctic char. The name comes from the Norwegian verb "prula" which means "boiling" or "seething".^[1]

Plura
Location of the river Show map of Nordland Plura (river) (Norway) Show map of Norway
Location
Country	Norway
County	Nordland
Municipalities	Rana Municipality
Physical characteristics
Source	Kallvatnet
• location	Rana, Norway
• coordinates	66°14′23″N 14°46′22″E / 66.23960°N 14.77283°E / 66.23960; 14.77283
• elevation	564 metres (1,850 ft)
Mouth	Ranelva
• location	Rana, Norway
• coordinates	66°20′20″N 14°19′26″E / 66.33879°N 14.3239°E / 66.33879; 14.3239
• elevation	19 metres (62 ft)
Length	27 km (17 mi)
Basin size	437 km2 (169 sq mi)
Basin features
River system	Ranelva

The Plura river flows both over and beneath the ground, and it has the longest subterranean flow in Norway at 3.8 kilometres (2.4 mi). Until 1964, Plura was a large river, washing limestone out of the mountain, creating several caves/tunnels down through the Plurdalen valley. Through the Pluragrotta cave, about 20,000 cubic metres (710,000 cu ft) of water passed each minute. The Kallvatnet dam made the river Plura almost dry, and the water in Pluragrotta cave became standing still like in a water seal.