Mecca clocktower showcases astronomy Visitors and tourists flock to the four-storey Clock Tower Museum filled with models and structures on astronomy and galaxies, and line up behind a metal fence overlooking the Kaaba, a black structure inside the Grand Mosque towards which Muslims around the world turn to pray, to take in the panoramic views of the mosque and the sprawling holy city. The Clock Tower is the main high-rise building in a complex of seven towers, comprising some 3,000 hotel rooms and apartments.