Big Ben is possibly London’s most famous landmark. The 98 metres high clock tower is named after the largest bell weighing over 13 tonnes. The clock tower was completed in 1859 and the great clock started on 31st May, with the great bell’s strike heard for the first time on 11th July the quarter bells first chimed on 7th September. Each clock face is over 7 metres in diameter. Old pennies act as counter- weights to ensure Big Ben keeps time to the nearest second.