Construction of which of these famous landmarks was completed first?

I recently read a review from a tourist who complained that Big Ben shouldn't have been built so near the river Thames as he fell in while trying to take a photo of it !

AndyV5615, not anymore it’s not. As above, now known as Elizabeth Tower. Since 2012.

The clock tower is called St. Stephens tower.

Thank you, Guy Ritchie's "Sherlock Holmes" based abouts the 1890's... Big help :)