From quirky to downright weird, a guide to the most unusual places to stay around the world, featuring the world's best spaceship treehouses, ice suites, underwater hotels and glass igloos.

InterContinental Shanghai Wonderland

The space-age InterContinental Shanghai Wonderland hotel trickles down the scarped slopes of an abandoned quarry, and jumps out in a city better known for its rising skyscrapers. It has been labelled the world's first underground five-star resort – and the bottom two floors sit underwater. Expect waterfall views from each room (except for the submerged spaces, where schools of fish will float past instead).

Read more: Shanghai's newest luxury hotel – built into the side of a quarry