Designed by the French architect Michel Pinseau, the Hassan II Mosque is the largest in North Africa, and the third largest in the world. The mosque stands on a promontory looking out to the Atlantic Ocean, the sea bed being visible through the glass floor of the building’s hall. The walls are of hand-crafted marble and the roof is retractable. A maximum of 105,000 worshippers can gather together for prayer: 25,000 inside the mosque hall and another 80,000 on the mosque’s outside grounds. Work on the mosque was started in 1980, and was intended to be completed for the 60th birthday of the former Moroccan king, Hassan II, in 1989. However, the building was not inaugurated until 1993. Authorities spent an estimated $800 million in the construction of the building.. The minaret is 60 stories high topped by a laser, the light from which is directed towards Mecca.