World’s most expensive buildings

Illustration: Ashrafun Naher Ananna/TBS Creative
Masjid al-Haram, Islam's holiest site, began as a simple stone enclosure around the Ka'aba in the 7th century and has since expanded through Ottoman arcades and vast prayer halls. Its latest transformation, the 'Third Saudi Expansion' launched in 2008, has added massive prayer space, modern facilities, and infrastructure to serve up to 4 million Hajj pilgrims annually.

Source: Sotheby's