Clock on Abraj Al Bait Tower,at the top of the Hotel Tower: The hotel tower is topped by a four-faced clock, visible from more than 25 kilometres (16 miles) away, which is the largest clock in the world. The clockhouse and the spire are 200meters high. Each of the clock's four faces is 46 metres (151 feet) in diameter and will be illuminated by 2 million LED lights, alongside huge Arabic script reading: “Allah is the Greatest” on the north and south faces and on the west and east the "shhara". Four golden domes on pillars on all the corners are also present. Another 21,000 white and green colored lights, fitted at the top of the clock, will flash to signal Islam's five-times daily prayers, and will be visible as far as 29 kilometres (18 miles) away. The clock's four faces is covered with 98 million pieces of glass mosaics.