Three people including at least one tourist were hurt Thursday following a landslide at Navagio beach on the island of Zante, one of Greece's most popular travel destinations, state agency ANA said.
"There was a rumble and a rock fell, followed by a larger rock and then another. They whipped up a whirlpool that overturned (three) boats," an eyewitness told the agency.
Authorities shut down access to the beach, which lies at the foot of a 200-metre (650-foot) cliff and is accessible only by boat, as a precaution.
Hundreds of people were on the beach at the time, including children.
The injured are not believed to be seriously hurt.
Navagio is one of Greece's most popular beaches, taking its name from the remains of a cargo ship that was wrecked there nearly 40 years ago.
The site is also favoured by bungee jumpers and other extreme sports enthusiasts.