Aldgate was one of the original Saxon London city gates of which there were four. The name may derive from the words ‘ale’ (most interesting), ‘old’ or Old English ‘ael’, meaning free or open. Aldgate is the closest the Circle Line gets to having its own station and it definitely, and uniquely, has its own platforms here. There are two extra platforms used as a terminus for some Metropolitan Line trains. Sadly, Aldgate was the site of one of the 7/7 attacks. A holy warrior blew himself up on a Circle Line train from Liverpool Street as it approached Aldgate: apart from himself, he killed seven people in the explosion. There is a modest memorial to the seven victims in the ticket hall.