The world's first floating, rotating (floatating?) hotel building

Antalya is a city of around 800,000 people on the Southern Mediterranean coast of Turkey. Like most cities in that region, it has played host to a revolving cast of empires over the centuries, from the Romans, to the Byzantines to the Ottomans and Turks. Nestled between a stunning coastline and majestic mountain ranges, it's known as one of the most beautiful cities in Turkey, and it's also the site of one of the world's most unusual hotels. The Hotel Marmara Antalya features the only fully rotating hotel building in the world - and the way they've done it is fascinating.

The Hotel Marmara Antalya's main building is an ordinary 214-room hotel building overlooking the dramatic scenery around one of Turkey's most beautiful cities (see the gallery for gratuitous scenery photos).

But its smaller "revolving loft" is an engineering marvel and a pinnacle of luxury. Featuring only 24 rooms, this cylindrical tower cost US$12 million to build when it was completed in 2005, and the whole building is designed to gently rotate through 360 degrees over a period of between 2 and 22 hours.

To accomplish this, the entire 2750-ton building is floated in a special pool system containing 470 tons of water. The lower three floors are submerged under the water, while the upper 3 floors are treated to a slowly rotating panoramic view of the area.

Because the building is floating, friction is minimized and the whole thing's rotation is assisted by just six 1kW electric motors at the bottom. Special systems needed to be developed to deliver electricity, plumbing, heating and air conditioning to the rotating loft. The first building of its kind in the world, the loft won the Marmara Antalya a Worldwide Hospitality Award in 2007 for the Most Innovative Concept in Luxury Hotels.

Beyond the spinning tower, the Marmara is well-regarded as a luxury independent hotel. Rooms can be had for under 100 Euros (US$150) or over 400 Euros (US$600) depending on what you go for.