More than 1,100 marathons take place in the U.S. each year, and the latest statistics by Running USA indicate more than 500,000 runners finished a marathon last year.

So what makes a marathon stand out among the crowd of more than 1,000? Several factors contributed to our compilation of “bucket list” marathons, including history and tradition, a unique experience, a scenic course and, really, any criteria that would make a runner designate a race as a “must-do.”

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Here are 15 marathons you should be sure to cross off your to-do list:

Boston Marathon
New York City Marathon
Chicago Marathon
Marine Corps Marathon
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Big Sur International Marathon
Rock 'n' Roll Las Vegas Marathon
Honolulu Marathon
Walt Disney World Marathon
Twin Cities Marathon
LA Marathon
Houston Marathon
Rock 'n' Roll San Diego Marathon
Grandma's Marathon
Country Music Marathon
Austin Marathon