The 750,000-brick Kennedy Space Center. Using 1,506 square feet, it took 2,500 hours to build. It includes a 6.13ft-tall Space Shuttle on the launch pad, the space center with a 9ft-long Saturn 1B rocket, and the Vehicle Assembly Building—8ft long x 6ft high x 5ft wide—made out of 50,000 Lego bricks. I know. Mindblowing. This thing is so massive that it can probably affect Earth's orbit.