Boston Marathon is world's oldest

, April 16: The 2013

Marathon is the 117th edition of the event, which was first held in 1897. It is the world's oldest annual

and one of six World Marathon Majors.

The race, which runs through 26 miles 385 yards (42.195km), is always held on Patriot Day, the third Monday of April. It attracts about 20,000 athletes around the world each year, one of the world largest marathons, reports Xinhua.

The Boston Marathon is the most widely-viewed sporting event in New England with about 5,00,000 spectators.

Two explosions occurred at the 2013 Boston Marathon on Monday, causing at least three deaths and over 100 injuries.

IANS