The distance of an Olympic marathon is precisely 42.195 kilometers, which is approximately 26.2 miles. This distance has been standardized since the 1908 London Olympic Games when the course was extended to allow the race to start at Windsor Castle and finish in front of the royal box at the Olympic Stadium. The marathon has since become a symbol of endurance and human resilience, attracting participants from around the world to compete at this elite level in the Olympic Games.