The Abraj Al-Bait Towers also known as the "Mecca Royal Clock Hotel Tower" is a complex under construction in Mecca, Saudi Arabia by the Saudi Binladin Group. Upon completion, the tallest tower in the complex would stand as the tallest building in Saudi Arabia, and the tallest and largest hotel in the world, with a planned height of 601 m (1,972 ft). Upon completion, the structure would have the largest floor area of any structure in the world with 1,500,000 m2 (16,150,000 sq ft) of floorspace. This is the same as Terminal 3 at Dubai International Airport, in the United Arab Emirates which is also under construction. It will also surpass the Emirates Park Towers in Dubai as the world's tallest hotel. It is also the second tallest building under construction. The entire project is estimated to be completed in the autumn of 2011.
The site of the complex is located across the street to the south from an entrance to the Masjid al Haram, which houses the Kaaba, the holiest site in Islam. In order to start construction, the historic Ottoman Ajyad Fortress had to be first completely demolished. To accommodate worshippers who visit the Kaaba, the Abraj Al-Bait Towers will have a large prayer room capable of holding nearly ten thousand people. The tallest tower in the complex will also contain a seven-star hotel to help provide lodging for the over five million pilgrims who travel to Mecca annually to participate in hajj.
In addition, the Abraj Al-Bait Towers will have a four-story shopping mall and a parking garage capable of holding over a thousand vehicles. Residential towers will house permanent residents while two heliports and a conference center are to accommodate business travelers. In total, up to 100,000 people could be housed inside the towers. The project will use clock faces for each side of the hotel tower. The highest residential floor will be at 450 m (1,480 ft), just below the clocks. The clock faces will be 43 × 43 m (141 × 141 ft), the largest in the world. The roof of the clocks will be 530 m (1,740 ft) above the ground, making them the world's most elevated architectural clocks. A 71 m (233 ft) tall spire will be added on top of the clock giving it a total height of 601 m (1,972 ft), which will make it the second tallest building in the world when completed.