A fixture of the London landscape and soundscape, Big Ben, is falling silent for four years. The bell will cease its regular tolling while extensive repairs are made to the famous clock tower that looms over the Palace of Westminster, the home of the British Parliament.

The massive bell will mark the hour for the last time at noon on Aug. 21 and then pause for four years while the Elizabeth Tower, which houses the Great Clock and the Great Bell, aka Big Ben, is restored. A larger restoration of the Parliament buildings is likely to begin in the early 2020s, according to a Parliament website.

Quieting Big Ben's mighty bongs will help preserve the hearing of workers involved in the project.

The keeper of the Great Clock, Steve Jaggs, said in a statement that the pause "is a significant milestone in this crucial conservation project." If you're in London next Monday you may want to accept Jaggs' invitation to gather in Parliament Square "to hear Big Ben's final bongs until they return in 2021." However, Big Ben will still bong for important national events such as New Year's Eve and Remembrance Sunday.

The Great Bell has chimed nearly every hour for the past 157 years. It has had previous breaks in service for maintenance and conservation in 2007, in 1983-1985 and in 1976. The 13.7-ton bell, which was forged in the 1850s, is accompanied by smaller chimes that ring out each quarter hour.

The Great Clock has a Victorian-era clockwork mechanism that triggers the bell and chimes. That mechanism and the clock's four faces will also get refurbished, which will require the faces to be covered.

To make sure Londoners don't get completely disoriented and lose track of the correct time, Jaggs says at least one clock face will remain visible. It will keep time with the aid of a modern electric motor, while the Victorian mechanism is being repaired.

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