Ultimate Underground Xtreme Experience at the Deepest Slate Mine in the World | Virgin Experience Days / Voucher Gift Virgin Experience Days For Couples/Him/Her/Mum/Dad/Boyfriend/Girlfriend/Wife/Husband/Partner/Family Things To Do | Push Yourself to the Limit With This Ultimate Underground Xtreme Challenge at the Deepest Slate Mine in the World. Perfect for Those on the Hunt for Their Next Adrenaline Rush, the Go Below Ultimate Xtreme Challenge Lasts Approximately Seven Hours. It Features Nine Ziplines Including ‘Goliath’, the World’s Longest and Deepest Underground zip Ride and the World’s First and Only Underground Freefall. You’ll Also Climb, Abseil and Traverse, as Well as Cross Rickety Bridges, Steel Pins and old Planks of Wood. Certainly not for the Faint Hearted, This is an Experience That’s Sure to Leave you Buzzing Long After It’s Over. | Wales - Gwynedd