World's first artificial surfing lake
Britain's first artificial surfing lake is due to open in Snowdonia next year.
Revolutionary technology means that 10ft (3m) waves can now be created at the touch of a button.
A giant man-made lake three times the size of Wembley stadium is under construction in the Welsh mountains, with a second site planned for Bristol.
The mechanical wave is a world first and is set to transform the sport of surfing, giving it the potential to be considered as an Olympic event.
BBC science correspondent Claire Marshall was given exclusive access to the prototype being developed in Spain.
Camera/editing: Tony Smith