The intersection of 16th Street and the Monon Trail in downtown Indianapolis. Photo: Arika Herron/Axios In honor of Global Running Day, we're celebrating one of Central Indiana's favorite pavements to pound. The big picture: Today, the popular Monon Trail spans roughly 30 miles from downtown Indianapolis north through Hamilton County. It's largely considered one of the city's best amenities and its success has helped catalyze the creation of new trails statewide.