Headlining beside one of the world's largest squares, Esfahan's Imam Mosque is a tiled wonder. Completely covered, inside and out, with pale blue and yellow ceramic tiles (which are an Esfahan trademark), it's a stunning 17th-century mosque, with its tiles seeming to change color depending on the light conditions. The main dome is 177-feet high and intricately patterned in a stylized floral mosaic, while the magnificent 90-foot high portal is a supreme example of architectural styles from the Safavid period (1502-1772). The mosque sits askew to the square, at about 45 degrees, so that it faces Mecca.