dams

The largest dam changes depending on whether you rank by height, reservoir, concrete volume, or hydroelectric output. Here is the science behind each record.

The Burj Khalifa in Dubai stands 828 meters tall — for context, you could stack almost two Empire State Buildings on top of each other and still not reach its antenna. But height is only one dimension of 'largest.' The world's longest bridge stretches 164.8 km across China. The Great Wall of China, including all branches, runs over 21,000 km. The largest building by floor area is a Boeing factory in Washington State that covers 398,000 square meters under a single roof. What engineering limits the next record depends on which dimension you're measuring and why physics makes every additional meter harder than the last.