The Boston Marathon is the world's oldest annual marathon and ranks as one of the world's best-known road racing events. Organized by the Boston Athletic Association (B.A.A.), it traditionally takes place on Patriots' Day in April and attracts both elite and amateur runners from around the globe. The race starts in Hopkinton, MA, and finishes on Boylston Street in Boston.
             
           
                
                    Course Terrain 
                
                
                    The course consists of paved city streets, beginning in the rural township of Hopkinton, proceeding through several cities and towns including Ashland, Framingham, Natick, Wellesley, Newton, Brookline, and finishing in Boston. Notable features include the challenging Newton Hills and the famous Heartbreak Hill.
                 
            
            
                
                    Elevation Changes 
                
                
                    The course features a net downhill overall, starting at 475 feet above sea level and finishing at about 16 feet. However, there are several rolling hills, including the four Newton Hills, with Heartbreak Hill peaking at approximately 20 miles into the course, which is notorious for its difficulty.