It’s the type of late-spring afternoon that nudges all of New York City toward outdoor activities, and Marcus Garvey Park in Harlem is buzzing. The 20-acre public park sits just south of the neighborhood’s main boulevard, 125th Street, where shiny new apartment buildings and retail stores have been popping up around cultural landmarks like the Apollo Theater in recent years, signaling a steady shift toward gentrification. Today there are dog walkers and joggers, kids getting out of school and burning off some excess energy, elderly folks looking for some fresh air, and, of course, the guys hustling chess games. But I’m headed to the southeast corner of the park to do something I haven’t done in a long time—an outdoor workout.

My instructor is Luis Melo (friends call him Melo), 43, who functions as the unofficial manager of the unofficial community gym where we’ll be working out, the Lion’s Den. He waves me over to an exercise area that’s made up of a collection of faded blue pullup, dip, and monkey bars, basically your standard metal playground fare from the days when children’s safety was of little concern; it doubles nicely for calisthenics. But there are a few more freshly added pieces of equipment there, too, including a heavy bag, a bench, assorted dumbbells—and even more gear stowed in a large green storage container nearby.

“As the summer comes, we’re going to put more of it out, and it’s going to just give people more motivation even to come here,” Melo says. “There’s people that walk by that just be like, ‘Oh my God, I can’t believe that your space is here.’ ”