The Boston Marathon is an annual marathon hosted by several cities in greater Boston in eastern Massachusetts, United States. It is always held on Patriots' Day, the third Monday of April. Begun in 1897, inspired by the success of the first modern-day marathon competition in the 1896 Summer Olympics, the Boston Marathon is the world's oldest annual marathon and ranks as one of the world's best-known road racing events. It is one of six World Marathon Majors, and is one of four major events held in the United States through the years of both World Wars (Kentucky Derby, Rose Parade, and Westminster Kennel Club Dog Show are the others). Since 1897, the Boston Athletic Association (B.A.A.) has managed this event. Amateur and professional runners from all over the world compete in the Boston Marathon each year, braving the hilly Massachusetts terrain and varying weather to take part in the race. The event attracts 500,000 spectators each year, making it New England's most widely viewed sporting event. Though starting with 18 participants in 1897, the event now attracts an average of about 30,000 registered participants each year, with 30,251 people entering in 2015. The Centennial Boston Marathon in 1996 established a record as the world's largest marathon with 38,708 entrants, 36,748 starters, and 35,868 finishers The 2016 event will be the 120th running of this annual competition!