The Boston Marathon runs 26.22 miles (42.195 km). Photos taken at Heartbeak Hill. Heartbreak Hill is an ascent over one-half mile of the Boston Marathon course, between the 20 and 21 mile marks. It is the last of four "Newton hills", which begin at the 16 mile mark. Runners come from all nations and all walks of life. Some are professional runners, some run for charity, some for personal goals, yet others run in memory of loved ones. There are first time runners and also runners that will be running for the 42nd time. The youngest is 18 the oldest 81. Winners all.