Scheduled to open in 2009, the Hydropalace in Qingdao, China, will be anchored in the Yellow Sea in water that is 16 to 20 meters deep at low tide. Guests will arrive at the hotel by yacht, which will also stop at a planned land-based hydrotower, scheduled to open for the 2008 Olympic Games in Beijing.

Ice Hotel

Quebec, Canada

The Ice Hotel is created anew each year out of 15,000 pounds of snow and 500 pounds of ice. The 34-room hotel features an ice chapel, two art galleries and a host of outdoor activities. The temperature inside the hotel ranges from 23 to 28 degrees Fahrenheit, and the beds are carved from ice. You don’t sleep directly on the ice, though–there’ s a wooden plank between the ice and a comfy mattress, plus you’re insulated with a special sleeping bag that can withstand the harshest climes (-40 degrees Fahrenheit). Happily, the bathrooms are not frigid–the heated facilities are in the adjacent hotel.

Casablanca Hotel
New York City
Ever wanted to live like Bogey? The 48-room Casablanca Hotel in Times Square features a Moroccan décor complemented by Rick’s Café, named for the restaurant in the classic 1942 film featuring Humphrey Bogart and Ingrid Bergman.

Propeller Island City Lodge
Berlin, Germany

Would you rather sleep in a coffin or in a bed atop a castle? These are just a couple of options available when visiting the Propeller Island City Lodge, where each of the 31 rooms embrace a different theme. From the orange room to the symbol room–tiled entirely with wooden blocks painted with 300 different symbols–this gallery-esque spot gets those creative juices pumping.

Library Hotel

New York City
Appropriately located near the New York Public Library, the hotel has 60 rooms on 10 floors. Each floor is designed after one of the 10 categories of the Dewey Decimal System, such as Math and Science and Religion, and each room houses part of the hotel’s collection of 6,000 books.

The Pitcher Inn
Warren, Vt.
The nine rooms and two suites at The Pitcher Inn are designed on themes such as “School,” “Trout” and “Calvin Coolidge.” We’re not just talking variations in wallpaper–the “Stable” suite has a hay chute opening into it. Guests don’t rough it, however. The inn is a Relais and Chateaux property, and it includes a spa and dining room that uses fresh local and regional ingredients.

Ariau Towers Hotel
Brazil
Not for the acrophobic, this hotel lets you sleep in the treetops of the Amazon Rainforest. “Tarzan’s house,” for example, is perched on stilts 80 feet above the ground. Situated on the bank of the Negro River, Ariau’s apartments, suites and tree houses are linked by a series of catwalks.

Beckham Creek Cave Haven

Parthenon, Ark.
A “luxurious cave” may sound like the ultimate contradiction. This property, built into the Ozark Mountains, features natural rock walls and ceilings as well as Jacuzzi bathtubs and large windows for letting in light. Built as a Cold War bomb shelter by John Hay, founder of Celestial Seasonings tea, it’s now a base from which to hike, bike and explore local springs.

Winvian
Morris, Conn.
At Winvian, lodging options range from a helicopter to a log cabin. The hotel features 18 individually designed cottages and one suite located in the main house. Included in the rates are all meals and drinks (excluding a reserve wine list), Vespa scooters, horseback riding and other activities.

Jules Undersea