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 to accommodate 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 contains a five-star hotel with 1,618 (!) rooms and suites operated by Fairmont Hotels and Resorts. It spreads on a mind-blowing 16,145,866 square feet (1,500,000 square meters) floor area.
It's towering right above Islam's holiest site, offering an unprecedented panoramic view of the Masjid al-Haram - the Great Mosque of Mecca.
Lebanon-based architectural group Dar Al-Handasah designed the complex, which features the world's tallest and largest clock.