Mendenhall Ice Caves - 8150 Mendenhall Loop Rd, Juneau, Alaska, USA

Lying in the Mendenhall Valley is the Mendenhall Glacier, which is 12 miles in length, and 12 miles from Juneau in Alaska. Inside the glacier there are amazing blue ice caves, which involve kayaking to the edge of the ice and climbing over the glacier to access them. You would need to visit fairly soon, as due to climate change the glacier is receding. A visit to the caves has been called “surreal” and “otherworldly,” with its amazing blue glow.