The hole – big enough to swallow a large boat – looks like a feature on an alien planet.
However, the seawater levels in the Pacific Ocean are actually perfectly safe, because the hole – called Thor’s Well, and sometimes the ‘gate to hell’ – is actually around six metres deep.
At high tide water bursts upwards out of the well in spectacular fashion, an event that never fails to delight onlookers.
It makes for dramatic photographs. As a result tripods often populate the surrounding rocks, with tourists anxious to capture the violent surges on film.
According to Gary Hayes, from Traveloregon.com, Thor’s Well – located in the Cape Perpetua Scenic Area near Yachats – probably started out life as a sea cave.
He said: “Formations like Thor’s Well and Spouting Horn are typically formed over long periods of time geologically.
“They begin as a sea cave and eventually the top of the cave collapses, leaving an opening where the tide surges from below to send water shooting upward with dramatic force.”
He advised that if you visit, it’s best to keep your distance.
He added: “It can be viewed safely from the highway viewpoint at Cook’s Chasm or lower viewpoints along the paved trail.”
Belize is home to a similarly amazing ocean hole – called the Great Blue Hole. The spectacular submarine hole is over 300 metres in diameter and over 90 metres deep and is very popular with scuba divers.