Here’s a rare look inside the Booming Ice Chasm beneath the Rocky Mountains. It got its name for the incredible acoustics – as falling rocks crash and ‘boom’ when they tumble down the 459-feet deep cave. Inside, the crystal clear ice is several meters thick – and explorers say navigating across it makes them feel like they are flying. Continue reading for more pictures and information.

These mind-blowing images were captured by Belgian photographer Francois-Xavier De Ruydts, 30, on an exploration to the Crow’s Nest Pass area of Alberta, Canada, this past July. This cave is also known as the ‘cold-trap cave’ where cool winter air settles into the depth and is never able to escape. Since the frozen ice slides makes people feel like they’re flying, one slip you’ll be hurtling down the frozen water slide slamming into the wall below.