Buildings that Scrape the Sky
The worlds first metal-frame skyscraper, the ten-storey Nome Insurance Building (52 m, 171 ft), was erected in Chicago in 1884-5. It was then the tallest office block in the world - a title now held by the Sears Tower, also in Chicago. However, the world's tallest structure made of galvanised steel and completed in 1974 - is the Warszawa Radio Mast near the city of Plock in Poland.
Some of the World's Tallest Structures
Name	Location	Height
		metres	feet
Warszawa Radio Mast	Plock, Poland	646	2120
CN Tower	Toronto, Canada	551	1814
Sears Tower	Chicago, USA	443	1454
World Trade Center Demolished by terrorists	New York, USA crashing aircraft into it	411 11 Sept	1350 2001
Empire State Building	New York, USA	381	1250
John Hancock Center	Chicago, USA	343	1127
Centrepoint Tower	Sydney, Australia	305	1000
Eiffel Tower	Paris, France	300	984