There were the six ships, the tall white world, the sandy plain and the hills.

The keystone of the project would be a 150-story skyscraper, the world's tallest.

She went to the Woolworth Building, then the world's tallest.

Enter into the tall world of trees and learn about a handful of the more than 100,000 tree species.

It'll be a great building, the world's tallest or not.

The building is the world's tallest and a symbol of the Chicago skyline.

Today, Chicago's skyline is among the world's tallest and most dense.

Across the plain the tall white world seemed to watch with silent amusement.

Today, the London Eye, above, is at 450 feet the world's tallest.

The dam, which was due for completion in 2019, would be one of the world's tallest at 152m (500ft) high.