Vertical City

The Sears Tower is still the tallest tower in the US and was the tallest building in the world for 25 years.

This spire in Malmo, Sweden is a world-class design and is the tallest building in Scandinavia.

The first skyscraper to be constructed on Ground Zero has taken skyscraper safety to new levels.

Keith Keaveney visits the world's first eco-friendly skyscraper in Germany.

The tallest residential building in the world is the most exclusive address in the Southern Hemisphere.

Torre Mayor can withstand earthquakes that would obliterate average towers.

Torre Mayor can withstand earthquakes that would obliterate average towers.

Built by Cesar Pelli, this tower is in a bleak area of the town.

Cologne Cathedral is a reminder of the times when towns would compete to build higher.

The United Kingdom's tallest skyscraper, One Canada Square, changed London's skyline in the 1990's.