Big Ben and the Palace of Westminster, London, England

London o'clock. Palace of Westminster, London, England

London's most famous clock tower isn't called Big Ben—that name belongs to the massive 13.5-ton bell inside. The Great Clock has marked time for Londoners since 1859, ringing from what is now known as the Elizabeth Tower, renamed in 2012 to honor Queen Elizabeth II during her Diamond Jubilee. At 316 feet tall, the tower is part of the grand Palace of Westminster. The clock has stopped only for maintenance and rare disruptions, such as bomb damage during each world war. Each of its four clock faces spans 22.5 feet, with the minute hands measuring 14 feet.

For centuries, the Palace of Westminster has stood at the heart of British politics. Originally built by Edward the Confessor in the 11th century, the palace has hosted Parliament since the 13th century. Previously a royal residence, it remained one until a fire in 1512 forced Henry VIII to relocate. A second devastating fire in 1834 destroyed most of the medieval complex, leading to the Gothic Revival design seen today. Architect Charles Barry led the reconstruction, while his assistant, Augustus Pugin, designed the intricate details. Covering about 27.8 acres, the palace houses the House of Commons, the House of Lords, and Westminster Hall, which dates back to 1097.