The Empire State Building Run-Up (ESBRU)—the world’s first and most famous tower race—challenges runners from near and far to race up its famed 86 flights—1,576 stairs. While visitors can reach the building’s Observatory via elevator in under one minute, the fastest runners have covered the 86 floors by foot in about 10 minutes. Leaders in the sport of professional tower-running converge at the Empire State Building in what some consider the ultimate test of endurance.