Mecca from the last 1,500 years have survived Saudi rule. Expansion of the city is ongoing and includes the construction of tall Abraj Al Bait Towers across the street from the Masjid al-Haram. The towers were the third tallest building in the world when completed in 2012. The construction of the towers involved the demolition of the Ajyad Fortress, which in turn sparked a dispute between Turkey and Saudi Arabia. The Zamzam Well is home to a celebrated water spring. The Qishla of Mecca was an Ottoman castle facing the Grand Mosque and defending the city from attack. However, the Saudi
Mecca infrastructure, home to structures such as the Abraj Al Bait, also known as the Makkah Royal Clock Tower Hotel, the world's fourth tallest building and the building with the third largest amount of floor area. During this expansion, Mecca has lost some historical structures and archaeological sites, such as the Ajyad Fortress. Today, more than 15 million Muslims visit Mecca annually, including several million during the few days of the Hajj. As a result, Mecca has become one of the most cosmopolitan cities in the Muslim world, although non-Muslims are prohibited from entering the city. "Mecca" is the familiar form