One of my current favorite engineering achievements would have to be the construction of the tallest free-standing structure in the world, Dubai's Burj Khalifa at 829.8m. Having a number of both architectural and engineering feats, this tower breaks boundaries by not only being the tallest skyscraper on the planet, but also taking titles with the highest outdoor observation deck, highest occupied floor, tallest elevator service, and longest elevator travel distance. One of the most intriguing innovations that came from the construction of this building was the pressurized pump system used to vertically pump concrete to record-breaking heights. Since nothing powerful enough existed pre-dating the tower, this had to be developed alongside its construction. There are many other engineering feats that were developed to aid the construction of the Burj Khalifa as well. Starting with the Y-shaped mat that served as the building's foundation---consisting of reinforced concrete supplied by almost 200 concrete piles! Or you cold look at the reinforced steel cylinder that went through the center of all the mats to maintain the building's stability. There are so many incredible details that went into this project that will continue to support the structures of our societies for years to come.