I am standing in William street, as the leaders sprint past before entering the tunnel at Kings Cross. As I look towards the starting place in Sydney's CBD the entire street is completely filled with participants. Some are sprinting, some are walking, some are in outrages costumes, and some are in wheelchairs. It is the Sydney City to Surf run finishing on Bondi Beach a distance of 14km with 80,000, participants making it the largest run of its kind in the world.