Teenagers have been filmed jumping from a clifftop known as Dead Man's Cove, where one man plunged to his death last year.
Footage shows the youths risking their lives to cool off during the weekend's heatwave, by 'tombstoning' 65 feet into the sea from the infamous spot in Plymouth, Devon.
They were filmed just six months after father of three Vincent Wagstaff plunged into the sea at the same place and died from multiple injuries.
The area is known by locals as Dead Man's Cove, and every summer thrill-seekers come from across the country to jump into the sea from the cliff.
Coastguards have repeatedly warned people to not take part in tombstoning as it is extremely dangerous.
The Maritime & Coastguard Agency said: "Jumping from piers, cliffs, rocks or other structures into the sea can be very dangerous.
"The depth of the water can dramatically change with the tide, and what was a deep pool at lunchtime might be a shallow puddle by teatime.
"You don't know what hazards may be lurking under the surface until you are hurt or worse.
"The shock of cold water may make it difficult to swim to safety and strong currents can quickly sweep people away."
Mr Wagstaff, 39, fell to his death in October after attempting to jump from the cliff into the sea, and his brother Peter has called for additional railings or bollards to prevent people from jumping off the edge so easily.
Although Mr Wagstaff's death was the first and so far is the only death in Plymouth, many people have been seriously injured by tombstoning.
In 2010, teenager Ben Thompson was left paralysed when he broke his neck in three places after jumping from an eight-foot wall at the same site.
In 2008 25-year-old Steven Andrews was paralysed when he fell 20 foot into three feet of water at Whitsand Bay.