Bizarre 22m-wide ‘portal to hell’ opens up in Californian lake – leaving locals baffled

 

The strange phenomenon took place in the Lake Berryessa reservoir in the eastern Napa Valley. If water levels in the reservoir, which lies at the top of the Monticello Dam, get too high, excess water can whirlpool into a gigantic hole. A 22-metre-wide (72 ft), 75-metre-long tunnel which functions as a drain hole (245 ft) swallowing around 1,360 cubic metres of water (48,000 cubic feet) per second when the lake rises above 4.7 metres (15.5ft).