Each year, millions of pilgrims flock to participate in the Hajj, a mandatory (once-in-a-lifetime) visit to the holiest city of Islam, Mecca.
As there are approximately two billion Muslims worldwide, the Saudi Arabian city had one of the biggest challenges to solve: accommodating all the travelers coming to see the Kaaba, the "House of God." And so they built a complex of seven skyscraper hotels costing $15 billion.
Makkah Clock Royal Tower is the fourth-tallest building in the world, rising to 1,972 feet (601 meters). The tallest tower houses a five-star hotel operated by Fairmont Hotels and Resorts. It has 1,618 (!) rooms and suites and a floor area of a mind-blowing 16,145,866 square feet (1,500,000 square meters).
It towers above Islam's holiest site, offering an unprecedented panoramic view of the Masjid al-Haram - the Great Mosque of Mecca. The Lebanon-based architectural group Dar Al-Handasah designed the complex, which features the world's tallest and largest clock.