The name "Big Ben" commonly refers to the tower as a whole, but it's really just the clock (13 tons)at Westminster Palace, the home of Parliament in the United Kingdom. It is, in fact, the world's largest four-faced clock, and is the third highest clock tower in the world. The clock became operational in 1859, and due to Metro construction, the tower has been experiencing almost 1mm/yr. sinking since 2003. The metro stop is "Westminster". Once you exit, you'll have an opportunity to take the typical picture of the metro sign out front. It is also across the London Eye , crossing the River Thames.