If you think you're ready for the next level in underground challenge, our Challenge Xtreme adventure will be just what you're looking for. After a short walk up to the entrance with stunning views on all sides, we enter the labyrinth of over fifty miles of tunnel and over a thousand spectacular caverns carved by the Victorians though the very heart of a mountain.

The going gets tough quickly, and it stays tough. Our route takes us over many lofty traverses - balancing on old beams or pipes over breathtaking voids of [Caver crossing a zip line underground] darkness. We cross ancient timber bridges and abseil off hideous drops to sink deeper and deeper under the earth.

Ultimately we reach the very bottom accessible floor of the mine - 1,300 feet under the mountain. It is here that we are at the very deepest point that can be reached in Snowdonia

ZipWorld Velocity set in Penryn Slate mine, North Wales is Europes longest zipline activity.

The historic slate mine is the venue to enjoy the thrills as we take you on a ride of a lifetime on two ziplines, the first a meagre 800m of torpedo speed down the Little Zipper before taking the 20 minute guided tour up to the launch pad of the 1600m Big Zipper. The speed test was initially 80mph and now they say 100mph... Whatever speed you fly at, the acceleration at launch is incredible and at an altitude of 700ft over the lake, the most amazing view (if you have your eyes open!).