World's tallest, coldest, greenest hotels

For travellers who like a hotel with a superlative attached, online hotel specialist hotels.com has come with a list of record-breaking hotels.

The hotels featured by Hotels.com (http://www.hotels.com/), part of the Expedia Inc group, all have the "-est" factor. Reuters had not endorsed this list:

1. World's Tallest Hotel: Burj Al Arab - Dubai

Currently the tallest operating hotel in the world until it is surpassed by Dubai's Rose Tower later this year, the Burj Al Arab stands 321 metres (1,050 feet) high. A self-rated 7 star hotel built on a man-made island 280 metres from shore, Burj Al Arab also boasts its own Rolls Royce fleet, Versace bedspreads, and private shopper and helicopter landing platform.

2. World's Largest Hotel (by no. of rooms): The Palazzo Resort Hotel & Casino - Las Vegas, USA

The Palazzo Resort Hotel & Casino, which operates under the same license as The Venetian hotel next door, has 8,108 rooms combined. The hotel is like a mini city, with a large selection of restaurants, fashion stores, its own casino, and seven pools.

3. World's Oldest Hotel: Hoshi Ryokan - Komatsu, Japan

The Hoshi Ryokan has been in operation for over 1,300 years. The 100-room hotel has been run by the same family for 46 generations.

4. World's Most Expensive Hotel Room: Royal Villa at Grand Resort Lagonissi - Athens, Greece

Featuring a dedicated butler, chef and pianist, the Royal Villa at Grand Resort Lagonissi is the world's most expensive hotel room at $50,000 a night. The room overlooks the Aegean Sea, which you can view from a private pool with a hydro massage device. The resort also has a private Lear jet.

5. World's Most Expensive Hotel to Build: Emirates Palace - Abu Dhabi

The Emirates Palace in Abu Dhabi, which opened in 2005, cost over $3 billion to build with silver, gold and marble used throughout the hotel and the 1,002 chandeliers made from Swarovski crystals.

6. World's Largest Hotel Room: Royal Suite in the Grand Hills Hotel & Spa - Broummana, Lebanon

The Royal Suite in the Grand Hills Hotel & Spa is set over six floors for a total 8,000 square metres (86,110 sq ft) with half of this living space and the rest two swimming pools, a garden, terrace and pavilions.

7. World's Coldest Hotel: Icehotel - Jukkasjarvi, Sweden

The Icehotel has rooms built entirely from ice and snow, decorated with handcrafted ice art and sculptures, an ice chapel licensed for marriages and baptisms, and two restaurants serving a range of Lappish and Swedish dishes. Activities include snowmobile trips, northern lights tours, and dog sled tours.

8. World's Highest Hotel (floor height): Park Hyatt - Shanghai, China

The Park Hyatt in Shanghai occupies floors 79 to 93 of the 101 story Shanghai World Finance Centre with views over the Huangpu River and the city skyline and located in the heart of Lujiazui business district in Pudong.

9. World's Highest Hotel (altitude above sea level): Hotel Everest View - Nepal

The Hotel Everest View is 3,880 metres (12,730 ft) above sea level and is set in the Sagarmatha National Park. All rooms have views of Mount Everest standing at 8,848 metres (29,030 ft) and the only direct access is by chartered helicopter.

10. World's Most Eco-Friendly Hotel: Daintree Eco Lodge & Spa - Queensland, Australia

Set in the world's oldest rainforest, Daintree Eco Lodge & Spa has 15 villas nestled inside the Daintree Rainforest, and is committed to complying with sustainable tourism standards. Practices in place include using solar power, low energy lights and an organic farm to grow its own produce.