While Big Ben is used as a nickname for the clock, strictly speaking, it is the main bell inside the clock, and it also often refers to Elizabeth Tower, at the north end of the Houses of Parliament.

大本钟其实是它的昵称。严格意义上来讲，在时钟里面是一个大鸣钟。这座塔又名伊丽莎白塔，坐落于英国国会大厦的北端。

youdao

"Big Ben" is officially the name of the 13.5 ton bell inside St Stephen's Tower, and not the name of the tower itself.

CNN: May 4, 2012 -- Updated 1058 GMT (1858 HKT)