The world's most iconic buildings were built in the heydey of the American century, and as New York became the capital for these innovative new skyscrapers, experts used cutting-edge tech to push engineering to new heights.

The World Trade Center and Sears Tower were record-setting skyscrapers made possible by cutting-edge engineering innovations, but just as these American icons set new standards in construction, dark and insidious forces were poised to undo it all.

The rise of colossal towers across the planet coincided with the surge of cutting-edge design, but just as these monoliths began breaking world records, new threats were on the horizon.

Today's greatest skyscrapers use cutting-edge tech to build sky-high micro-cities within their walls, and these innovative mega-builds are becoming the new engineering icons in Chicago, Dubai, Beijing, and other twenty-first century metropolises.

Dubai's Burj Khalifa is over 2,700 feet high and the tallest building in the world, and as engineers race to top this record-setting height with cutting-edge tech, a new 3,200-foot-tall building in Saudi Arabia is poised to take the crown.