Djamaa el Djazaïr

In January 2008 a German consortium — KSP Jürgen Engel Architekten with the engineers Krebs und Kiefer — won the international competition for a state mosque on the bay east of Algiers. Ground was broken on 16 August 2012, China State Construction Engineering built it, and the works were finished in 2019 at an official cost of about $898 million against an early budget nearer $1.5 billion. It is the third-largest mosque in the world after Mecca and Medina: 27.75 hectares, room for 120,000 people, a prayer hall for 37,000 on 618 octagonal columns under a dome fifty metres across and seventy high, and a square minaret of 265 metres, the tallest on earth, which also holds a museum and offices. The structure is engineered for a magnitude-nine earthquake, on a coast that lost much of Boumerdès in 2003. The project was criticised for its monumentality and its cost before it opened, and drew enormous crowds once it had.