Stalactites and stalagmites in a beautifully lit cave.

This foolish Victorian sea fort was converted to a deluxe hotel.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

With well over 130 falls and cascades to brag about, Hamilton, Ontario has earned its stripes as the waterfall capital of the world.

This natural sea cave hides a small wonderland of natural turquoise beauty.

Lost subway station nestled beneath Toronto's busy commuter line.

A Cuban artist reclaimed his impoverished neighborhood as a dreamy folk art kingdom.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.

The world's first ice hotel is still one of the most elaborate and beautiful.

A unique opportunity to stay the night in retrofitted sections of sewer pipe.

A Korean rock bassist's wild dream has become a reality at this completely insane boutique hotel.

From dragonfruit to mangoes to durian this Thailand resort allows guests to stay inside all manner of giant fruit.

A floating underwater hotel, created by a Swedish artist.

Stay in your own little bubble.

The ruins of this Alaska gold mine form a gorgeous ghost town.

The ghostly remains of what was once the world's richest copper mine.

This whimsical stacked cabin looks like something out of a children's book.

Mind-blowing carvings and fantasy ice scenes grace the largest year-round ice environment in the world.

One woman's dream became a train hotel in her backyard.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

Stay overnight in the world's most sleekly designed rabbit hole, free of charge.

Sleep in a glass pod dangling off a cliff.

Sleep snuggled in a sphere suspended atop the forest canopy of Vancouver Island.

Sleep in a climate-controlled plastic bubble for the night.