Treehouse hotels
Some hotels, such as the Costa Rica Tree House in the Gandoca-Manzanillo Wildlife Refuge, Costa Rica, or Treetops Hotel in Aberdares National Park, Kenya, are built with living trees as structural elements, making them treehouses.
The Ariau Towers near Manaus, Brazil is in the middle of the Amazon, on the Rio Negro. Bill Gates even invested and had a suite built there with satellite internet/phone.
Cave hotels
Desert Cave Hotel in Coober Pedy, South Australia and the Cuevas Pedro Antonio de Alarcón (named after the author) in Guadix, Spain, as well as several hotels in Cappadocia, Turkey, are notable for being built into natural cave formations, some with rooms underground.
Capsule hotel
A Hotel common in japan.
Ice hotels
Ice hotels, such as the Ice Hotel in Jukkasjärvi, Sweden, melt every spring and are rebuilt out of ice and snow each winter.
Garden hotels
Garden hotels, famous for their gardens before they became hotels, includes Gravetye Manor, the home of William Robinson and Cliveden, designed by Charles Barry with a rose garden by Geoffrey Jellicoe.
Underwater hotels
As of 2005, the only hotel with an underwater room that can be reached without Scuba diving is Utter Inn in Lake Mälaren, Sweden. It only has one room, however, and Jules' Undersea Lodge in Key Largo, Florida, which requires scuba diving, is not much bigger.
Hydropolis is an ambitious project to build a luxury hotel in Dubai, UAE, with 220 suites, all on the bottom of the Persian Gulf, 20 meters (66 feet) below the surface. Its architecture will feature two domes that break the surface and an underwater train tunnel, all made of transparent materials such as glass and acrylic.
Other unusual hotels
The Library Hotel in New York City is unique in that its ten floors are arranged according to the Dewey Decimal System.
The Rogers Centre, formerly SkyDome, in Toronto, Canada is the only stadium to have a hotel connected to it, with 70 rooms overlooking the field.
The Burj al-Arab hotel in Dubai, United Arab Emirates, built on an artificial island, is structured in the shape of a sail of a boat.
Boutique hotel
Boutique hotel is a term originating in North America to describe intimate, usually luxurious or quirky hotel environments. Boutique hotels differentiate themselves from larger chain/branded hotels and motels by providing personalized level accommodation and services / facilities.
Sometimes known as "design hotels" or "lifestyle hotels," boutique hotels began in the 1980s in major cities like New York, London, and San Francisco. Very often it is the Morgans Hotel in Murray Hill of New York, that is awarded with the title of first boutique hotel in the world. It was opened by Ian Schrager in 1984 according to design of Andrée Putnam.
Typically boutique hotels are furnished in a themed, stylish and/or aspirational manner. Although usually considerably smaller than a mainstream hotel (often ranging from 3 to 100 guest rooms), boutique hotels can often have hundreds of rooms in major cities. Guest rooms and suites are fitted with telephony and Wi-Fi Internet, air-conditioning, honesty bars and often cable/pay TV. Guest services are attended to by 24 hour hotel staff. Many boutique hotels have on-site dining facilities, and the majority offer bars and lounges which may also be open to the general public.
Despite this definition, the popularity of the boutique term and concept has lead to some confusion about the term. Boutique hotels have typically been unique properties operated by individials or companies with a small collection. However, their successes have prompted established multi-national hotel companies to establish their own brands. The most notable is Starwood Hotels and Resorts' W Hotels.
Currently, there is one publication dedicated to the boutique hotel, boutique DESIGN magazine, which is published quarterly. Boutique hotel resources are more commonly available online and there are a number of sytlized design and coffee table books highlighting various properties throughout the world.