Casablanca's Hassan II Mosque is all about the superlatives. It can host 25,000 worshippers at prayer and has the world's tallest minaret, topping out at a staggering 210 meters. Yet it's a subtle building as well, showcasing the best in Moroccan craftsmanship, from its intricate mosaics to carved wooden doors. It's one of the few mosques in the country that's open to non-Muslims. The guided tour around its precincts is well worth the experience.