Jeremy Jacobowitz and John Mitchell were on the hunt for treasure in Central Park. Mr. Jacobowitz consulted the coordinates on his phone as a misty rain fell. He and Mr. Mitchell were geocaching, and if past experience was any guide, they would most surely find something. In nine years as a geocacher, Mr. Jacobowitz has discovered more than 8,200 caches, as the treasures are known, ranking him very near the top of the heap among New York City players. Mr. Mitchell counts his haul at around 3,600.

If golf is a good walk spoiled, geocaching is a good walk enhanced by digital devices and GPS coordinates, where hidden treasures are in parks and other public spaces. “Treasures” may be a bit overstated. The prizes may be a sew-on patch, a Matchbox car, a piece of costume jewelry. Each cache includes a small notebook or scroll for the finder to log in their name and the date they found it. Then the cache is returned to its hiding spot.

Geocachers have been searching for treasures since 2000, but the avocation is picking up in popularity. These days, most everyone has the functionality for it on their smartphone, and social media has brought geocachers in particular regions together, encouraging them to share notes from their hunts.

Caches are listed at Geocaching.com, while NYCGeocaching.com offers a treasure guide for the New York area. Caches are often situated near offbeat landmarks, like Tom’s Restaurant in Morningside Heights, which stood in for the diner on “Seinfeld,” or the Midtown subway grate where Marilyn Monroe’s white dress famously fluttered, or the TriBeCa firehouse where the Ghostbusters gang convened.