A bizarre “portal from hell” with a strange spinning vortex effect has left people baffled after opening up in a lake.
The terrifying 75ft-wide hole acts as a huge drain for the Lake Berryessa reservoir, which lies at the top of the Monticello Dam in eastern Napa Valley.
Excess water whirlpools into the massive hole when water levels rise above 15ft, creating a weird and wonderful spinning vortex effect.
Around 1,360 cubic meters of water is swallowed by the spillway per second when in use, which then travels down a 250ft tunnel, according to the Mirror.
Engineers back in the 1950s built a spillway as an alternative to the more common chute, which is used to control the flow of water out of a dam or a levee.
With that in mind, architects constructed the drain-like feature in the dam as it narrows the gap between cliffs where it is situated and would have left the chute with nowhere to go.
Ever since, the hole has quite established the reputation among the community.
Hundreds of spectators in 2017 came to watch the awe-inspiring spectacle of the “portal” opening up.
Lake Berryessa can hold around a 52billion gallons of water before the excess begins to flow into the spillway.
The lake reached full capacity for the first time in 11 years back in 2018.
However, it opened up again in 2019 after a season of heavy rainfall, attracting thousands of curious onlookers.
Today, the hole is no longer a safety hazard, as the reservoir is roped off and prohibits swimming or boating.
However, back in 1997, Emily Schwalek died after being caught in the current while paddling in the area as she was swept down the pipe after holding on to the rim for about 20 minutes.
Footage of the hole has gone viral ever since it was posted on the social media platform Gfycat back in 2018, and later recirculated on reddit, and has raked in hundreds of thousands of views.
Some social media viewers were spooked by the show.
One comment read: “Why is there a giant hole in the middle of the lake where people swim, and why is there not a rope around?”
Another added: “That looks very unsafe.”
And a third stated: “That right there is the portal to Hell.”
Similar to the “portal from hell” in California, a fiery pit in Kazakhstan earned itself a similar nickname in the early 1970s when the ground collapsed during a Soviet gas drilling expedition.
The hole is 20 meters deep and 60 meters (190ft) wide. It is located in the Karakum Desert, about 160 miles north of capital city Ashgabat.
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