The CN Tower has fallen in stature a little bit. It's no longer the world's tallest free-standing structure. The Burj Dubai, a US$4.1-billion hotel, business, and residential complex under construction in the United Arab Emirates has surpassed the Toronto landmark in height. On Wednesday, the Burj Dubai soared slightly above the CN Tower's 553 metres and it's expected to reach even higher heights as construction continues. When it's finally complete, the ritzy new building will be 800-metres tall.