Two teenagers broke into Blackpool Pleasure Beach and went for a 30-minute joyride on a rollercoaster at 4am.
The pair scaled the locked gates of the amusement park and gained access to the control-room of the 82-year-old Blue Flyer ride, a wooden rollercoaster which can reach speeds of up to 15mph.
They were seen on CCTV using the children's ride, which is in the Nickelodeon Land part of the park and lasts one minute and 30 seconds.
Security guards found the teens, who also went into the T Cafe and reportedly threw food, at about 4.50am on Friday, June 17.
A 15-year-old boy was arrested by police on suspicion of burglary and dealt with by community resolution.
A spokeswoman for the park said: "The intruders gained access over barriers and locked gates, and managed to enter a control-room of the Blue Flyer ride at Blackpool Pleasure Beach.
"They managed to operate the ride some time before security patrols discovered them at 4.50am.
"From CCTV footage, we understand the intruders were at the ride for up to 30 minutes. During this time two youths can be seen on the ride.
"Following the break-in, the ride has been fully inspected and is operational and open to the public."
The spokeswoman added there was "no significant damage" caused to the T Cafe.
She added: "Security will continue to operate with vigilance over a 24-hour period across the 42-acre site, assisted by CCTV surveillance, monitoring activity on the grounds of Blackpool Pleasure Beach."
A Lancashire Police spokesman said: "At around 4.50am on Friday, June 17, we were called by security at Blackpool Pleasure Beach after they spotted two youths on the site on CCTV.
"A 15-year-old boy from Blackpool was later arrested on suspicion of burglary and was given a community resolution."