Big Ben: Clock Tower renamed Elizabeth Tower for Jubilee
12 September 2012 Last updated at 23:57 BST
Parliament's Clock Tower is being renamed The Elizabeth Tower this week to honour the Queen's Diamond Jubilee.
But to many people it will still be known as Big Ben, which is the name of the Great Bell within the tower.
The BBC's Adam Fleming climbed hundreds of steps inside the landmark, with tour guide Tim Redmond, although the sound of the famous bongs proved too loud for a BBC microphone.