The Hassan II Mosque in Casablanca is one of the most magnificent religious buildings constructed in the modern era and the third-largest mosque in the world, after those in Mecca and Medina. Completed in 1993 after seven years of construction by a workforce of over 10,000 artisans, the mosque sits on a promontory jutting out over the Atlantic Ocean, its base literally built upon the sea in fulfillment of a Quranic verse stating that God’s throne was built upon water. The minaret soars 210 meters into the sky, making it the tallest religious structure on Earth, with a laser beam at its summit pointing toward Mecca that is visible for 30 kilometers at night. The main prayer hall accommodates 25,000 worshippers beneath a retractable roof that opens to reveal the sky, while the esplanade outside holds an additional 80,000, and every surface is adorned with exquisite traditional Moroccan craftsmanship: hand-carved cedar ceilings, intricate zellige tilework in geometric patterns of breathtaking complexity, sculpted plaster muqarnas, and marble columns and floors imported from Agadir and Italy.

What makes the Hassan II Mosque exceptional for visitors is that it is one of the very few mosques in Morocco open to non-Muslims, and the guided tours provide a rare and illuminating window into Islamic art, architecture, and spiritual practice. The underground hammam (bathhouse) level, with its heated marble pools and ornate fountains, showcases traditional Moroccan bathing culture. The exterior is equally stunning, particularly at sunset when the white granite and green-tiled facade glow against the deep blue of the Atlantic, with waves crashing against the mosque’s foundations in a display of nature meeting human ambition.

Pro tip: Take the earliest morning tour at 09:00 when visitor numbers are lowest and the interior light is at its most beautiful. The surrounding Corniche promenade is perfect for a post-visit walk along the seafront. Dress modestly with covered shoulders and knees, and note that shoes must be removed inside, so wear something easy to slip on and off.