The Mangan Clock has been a landmark on Saint Patrick's Street since the 1850s. Mangan Jewellers, founder in 1817 and formerly one of the best - known shops on the street, erected the clock. In 1847, craftsmen at Mangan's built the four-faced clock on Shandon church steeple. This was reputed to be the largest four-faced clock in the world until the construction of Big Ben in London.
Mangan's shop narrowly escaped destruction in December 1920 when a British auxiliary threw a grenade into the shop, intending to ignite a can of petrol which he had placed there. The petrol did not catch fire although the grenade blew out all the windows of the shop. Mangan's shop ceased trading in the late 1980s, before the premises were demolished, along with many others, to allow for the construction of the Merchant's Quay Shopping Centre. The Mangan Clock, on its tall kerbside pedestal, has been incorporated into the recent refurbishment of St. Patrick's Street.