The monorail at Alton Towers had to be closed after two trains crashed.
An inquiry is being carried out into the cause of the crash which happened on Saturday morning.
There were no passengers on the trains at the time and the drivers were uninjured.
Ralph Armand, the Staffordshire theme park's director, said both trains were travelling at a slow speed when one ran into the back of the other.
He said the monorail had to be closed for most of the day while safety checks were carried out.
Visitors had to use buses to travel around the park.
The Health and Safety Executive will be informed.