The Great Mosque of Mecca, Masjid Al Haram is on the top of the list of most expensive buildings in the world. The total cost of its construction is $100 billion. It can accommodate up to four million people in both its outdoor and indoor praying areas. It covers 400,800 square meters. It surrounds the holy Ka’ba and is also home to black stone (Hajr e Aswad) and Maqam e Ibrahim (Ibrahim’s place of standing). It is a sacred place for Muslims and non-Muslims are not allowed to enter