Clad in Macedonian marble, the beautiful and absolutely mammoth Sheikh Zayed Grand Mosque is Abu Dhabi's landmark building and by far the most popular sightseeing attraction in the city. The mosque fuses Mameluke, Ottoman, and Fatimid design elements to create a harmonious and thoroughly modern mosque that celebrates Islamic architecture. Artisans used glass-work, mosaic tiling, and intricate carvings to spectacular effect on both the interior and exterior. It was opened in 2007 after nearly 20 years of construction. Able to hold 40,000 worshippers, it is the biggest mosque in the United Arab Emirates, and like the Sheikh Zayed Mosque in Fujairah, it is dedicated to the late Sheikh Zayed bin Sultan al-Nahyan. Non-Muslims are allowed into all areas of the mosque (including the vast library), and guided tours are available.