Tourists were left scratching their heads as a 15ft deep hole shooting out snails appeared on the beach in Exmouth, Devon.
A large part of the beach had to be cordoned off after a beachgoer reported the mystery hole to the Coastguard near Orcombe Point on Thursday afternoon.
Experts found the surrounding sand had holes appearing too.
East Devon District Council said a 100-metre squared cordon was put in place after concern was raised that the hole could have a much larger chamber underneath.
Exmouth Coastguard reported the incident on its Facebook page, writing: "At lunchtime today a concerned member of the public contacted HM Coastguard as a large hole was appearing at the eastern end of Exmouth beach, Orcombe Point area.
"The National Maritime Operations Centre dispatched Exmouth Coastguard team to secure the area and provide accurate information to East Devon District Council.
"On arrival a hole approx 15' x 15' had appeared and was filled with water.
"The surrounding sand was also soft, with fresh holes appearing nearby. A cordon was in place and safety advice was given to beach users.
"An incoming tide will be flooding the hole later this evening allowing EDDC time to consider how to deal with the hole. As this was now a matter for the local authority HM Coastguard returned to station."
According to witnesses, the hole was 'bubbling' and was also shooting out snails.
Kite surf instructor James Dart told the BBC: "I looked over and there were big plumes of water coming out of the beach it was all bubbling up much like a geyser, it was probably going about a foot above the beach - it was quite a tremendous sight.
"I got closer and saw plant matter coming up, a few snails coming out too. It was something to spice things up in the rain."
According to the Metro, a council spokeswoman said: "The beach is very popular with dog walkers and bathers who are being advised to avoid the cordoned off area.
"Heavy rain yesterday may be the cause of the hole – a natural phenomena – to have opened up."
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