1. The Capsule Inn, Japan

While Osaka's Capsule Inn is, without a doubt, one of the most uncanny hotels in the world, it surely isn’t the ideal lodging option for those looking for pampering and relaxation. Opened in 1979, Capsule Inn is the first hotel of this kind in the world, built to offer basic overnight accommodation in small, capsule-like spaces. The "rooms" are just big enough to accommodate a bed, a TV and small luggage – and the guest himself, of course, though you might not believe this at first glance.

2. The Ice Hotel, Sweden

The Ice Hotel has to be rebuilt every year with, well, ice, to support the structure. Once the season closes, the water used in making it is poured back where it came from – into the River Torne. Not just the structure is made out of ice, but all the rooms and everything they contain, from beds, bars, and chairs to the beautiful sculptures on the corridors.

3. The Library Hotel, USA

If your idea of a perfect vacation includes dreaming away about a life more interesting than yours with a good book in your hand, this is the place to be. The Library Hotel in Manhattan is a literature lover's paradise. Not only will you be surrounded by books in your room – you'll be surrounded by the books of your choice. There's a music literature room, for example, a math room, and even one filled with erotic books (wink-wink)!

4. Karostas Cietums, Latvia

Have you ever wondered what living in a prison must be like? Since you (hopefully) aren't going to find that out the "real way," better book a room in Latvia's Karostas Cietums, definitely one of the weirdest hotels in the world. A former military prison, the hotel gives you the opportunity to live the life of a convict – with the characteristic prison bunks, the "prison officials" giving you a hard time and even the typical food. Tempted yet?

5. Hotel Costa Verde, Republic of Costa Rica

Thought it was impossible to get a good sleep on an airplane? Book a room at Hotel Costa Verde and you'll surely change your mind! The hotel owner salvaged an old Boeing 727 and redesigned it to accommodate two guest rooms, each with private bathroom, kitchen and air conditioning. The airplane is perched on a 50 foot pedestal, and it juts out across the forest canopy like it just went through an emergency landing. Just so you know, you can go for a drink on its wing!

6. The Cake Hotel, UK

A very tempting entry on our list of uncanny hotels in the world, the Cake Hotel in Soho, London, as you've most probably guessed, is made of delicious edible materials. You can eat its walls, tables, tubs, windows and basically anything that catches your eye. Quick tip: the rugs are made of marshmallow garlands! Yum!

7. Palacio De Sal, Bolivia

If you ever get sick of all the sweets in the Cake Hotel, you might want to move on to Palacio de Sal, a place made entirely out of salt – including the beds, chairs, tables and even the sculptures. Unfortunately, there's this nasty rule that you can't lick the walls (something-something-sanitary-reasons), but you can dive in their saltwater pool and enjoy the saltiness of the air as much as you wish.

These were just a few of the many uncanny hotels in the world. Do you know of any others worth mentioning? Which one would you love most to visit?