The 2016 Boston Marathon at a glance

In this April 21, 2014, file photo, runners compete in the 118th Boston Marathon in Hopkinton, Mass. The 120th running of the historic footrace is scheduled for Monday, April 18, 2016. (AP Photo/Steven Senne, File)
In this April 21, 2014, file photo, runners compete in the 118th Boston Marathon in Hopkinton, Mass. The 120th running of the historic footrace is scheduled for Monday, April 18, 2016. (AP Photo/Steven Senne, File)

The planet's most venerable footrace began humbly enough, with just a handful of runners participating in the inaugural running on April 19, 1897.

Since then, it's become the most celebrated road race on Earth.   The 26.2 mile trek takes runners through eight cities and towns - Hopkinton, Ashland, Framingham, Natick, Wellesley, Newton, Brookline, and Boston.

This year's edition has drawn 30,000 competitors from 99 countries -- the third-largest field in the history of the race. Principal sponsor John Hancock Financial will award $830,500 in prize money.

Cheering them on will be an estimated 1 million spectators.

>> CLICK HERE TO SEE THE 2016 RACE COURSE MAP

The oldest participant this year is 84-year-old Jules Wikler from Medford, N.Y. Paul Goldfinger from Newton is the youngest at 18 years, 2 months and 18 days.

Authorities say security will be tight again this year after the recent attacks in Brussels, though officials know of no specific threat against the marathon.

Explore>> CLICK HERE TO SEE THE 2016 FINISH LINE MAP