DUBAI, United Arab Emirates - If the developers are right, Dubai in the United Arab Emirates will eventually have the world's tallest structure -- taller than even Toronto's famed CN Tower.

The Burj Dubai, currently under construction, already stands at 512 metres tall.

It's expected to end up being almost 700 metres high.

Toronto's tower, the world's tallest free standing structure, is 553 metres.

Formerly, Taipei 101 in Taiwan was the tallest building at 508 meters.

The Burj's actual final height is a closely guarded secret.

It is expected to be finished by the end of 2008.