Pleasure Beach bosses today warned daredevils they were risking their lives after four teenagers were filmed scaling the Big One.
The four were spotted clambering over the metal structure of the ride at 9.30pm on Saturday after the park had closed.
Shocking video footage shows the boys – some wearing backpacks – making their way down from a platform over 200 feet up at the top of the first climb where the ride takes a steep drop.
It appears they were walking down steps which are parallel to the main track.
A spokesman for the Pleasure Beach said three of the teenagers were apprehended by police but the fourth got away.
The gang were spotted by staff at the Big Blue hotel who raised the alarm with security staff at the park, which closed that night at 7pm.
The spokesman, who described the stunt as ‘terribly dangerous’, said: “At approximately 9.30pm on Saturday 22nd July, Blackpool Pleasure Beach’s uniformed security detained a group of criminal trespassers.
“The police were called immediately and they were then handed over to the Lancashire Constabulary.”
The three boys held by police were all from the south of England - Southampton, Aldershot and Fleet.