Legoland Dubai claims to have unveiled the tallest lego structure in the world, a 17-metre-high replica of the Burj Khalifa which has been built using 4.39 lakh lego bricks. The Burj Khalifa model, which weighs a tonne, took over 5,000 hours to build. Legoland Dubai, set to open on October 31, showcases 15,000 Lego structures.