To tower over someone or something means to be much taller than that person or thing.
Joan towers over her husband when she wears her smart high heel shoes.
The new skyscraper towers over the buildings downtown.
You call someone a tower of strength when you mean they are strong and supportive.
When my parents died my older brother was a tower of strength.
The Eiffel Tower is 324 metres high. It was built in 1889 and is visited by seven million people every year. It receives up to 30,000 visitors a day at the peak of summer.