The first modern mosque I ever visited in the world was this impressive one, with the waves of the Atlantic Ocean lapping underneath, in Casablanca, Morocco. It was my first real exposure to the modern interpretations of Islamic Architecture, which would become a passion, and a wonderful experience of the tranquility and peace inside mosques.
With doors large enough for the king to ride his horse through, the mosque is not intended to replicate older mosques that Morocco is also famous for, such as Le Tour Hassan in Rabat (#864), or the Kotoubia Mosque in Marrakech (#988), but to show Morocco's modern strength and piety, although many Moroccans do not consider the Hassan II mosque as sacred because infidels are allowed inside.
Next to the old medina in a spectacular location, it was at one time the world's 3rd largest religious monument with the world's highest minaret (210m). Finished in 1993 for the late king's 60th birthday, it required 10,000 craftsmen 5 years to finish. It was designed by a French architect, Michel Pinseau, and had the latest technology such as headed floors, electric doors and a sliding roof, although its traditional zellij mosaic tiles were painstakingly put in place one by one, an exemplar of Morocco's strong traditional artistry. Its cedar interior comes from the Middle Atlas mountains, its marble from Agadir, and its granite from Tafraoute, showcasing a strong Moroccan pride.
Source: Lonely Planet Morocco 6th Edition