Eiffel Tower: a tower made only of iron (1889, Gustave Eiffel)

Prudential (Guaranty) Building: an artistic skyscraper (1895, Louis Sullivan)

Chrysler Building: a celebration of the automobile (1930, William van Alen)

Seagram building: a simple and elegant tower (1958, Mies van der Rohe)

John Hancock Center: a city reaching to the sky (1969, Fazlur Rahman Khan)

Menara Mesiniaga: a bioclimatic tower (1992, Ken Yeang)

Torre Agbar: a festive tower (2005, Jean Nouvel)

Burj Khalifa: the tallest tower in the world (2010, Adrian Devaun Smith).