The world's biggest underground zip line is due to open this Friday is Snowdonia.
Zip World Caverns can be found in an underground slate cavern which is big enough to house 75 double decker buses.
This exciting new playground is covered in brightly coloured LED lights which reveal the depths of the cavern, which was cleared by hand for more than a year.
An intricate pulley system was put in place so that construction workers could have full access to the underground cave.
This fun, new attraction can be found in the historic mining town of Blaenau Ffestiniog and it is hoped that the unusual activity will help boost the economy of the area.
There are five short lines available for the training section of the activity and 10 long zip lines that form the main course.
The whole experience will last around three hours and visitors get the chance to explore the depths of the five caverns on offer.
Sean Taylor, commercial director of the Zip World Group, said: "There is literally no other place on earth that you can experience an attraction like Zip World Caverns. It's an adventure of epic proportions that pretty much anyone with an average level of fitness can accomplish."
The first official visitor to Zip World was Eric Jones, a famous 78-year-old explorer and rock climber.
He said: "I was extremely honoured to be granted first access to this new attraction, which is fantastic for the whole family to enjoy. It's a perfect way for people from all walks of life to experience the thrill of adventure, in a safe environment."
The attraction will open this Friday 22 May, will be open all year round and will cost £50 per person.