The cn tower is a shell structure, but it is also has materials piled up together so it is a shell structure and a mass structure.
CN Tower
because it just is okay
I suspect you are thinking of the CN Tower. But the CN Tower is not the world's largest structure, never was, and doesn't even come close. It is tall, very tall, but quite thin. The CN Tower was (but is no longer) the world's tallest free-standing structure.
Canada's highest structure is the CN Tower in Toronto.
because it just is okay
The CN Tower in Toronto, Ontario.
Direct quote from the Wikipedia article on the structure... "...Its name "CN" originally referred to Canadian National, t he railway company that built the tower..."
CN Tower
The CN Tower in Toronto Canada is a concrete observation structure mainly used for TV and radio broadcasting. It also contains a number of cell sites.
eiffel tower is a frame structure.
The CN Tower is largely poured concrete.