If you thought New York City wasn’t a hotbed for camping, hiking or rock climbing interest, think again.

“There’s definitely demand in New York City for outdoor recreation activities that are guided,” said Melissa Abramson, manager of outdoor programs and outreach for the tri-state area for REI, an outdoor retailer that offers free and fee-based classes in dozens of recreational topics through its Outdoor School. “We can’t seem to schedule enough climbing classes.”

Beyond climbing, some of the most popular classes in the region include wilderness survival skills, paddling and navigation basics.

“With all the technology that we have — smartphones having navigational capabilities and GPS devices — people are really interested in learning the basics of operating a compass and reading a map,” Abramson said.

To help get more people outdoors this summer, REI is ramping up its usual offerings with its National Free Weekend of Outdoor School. From July 30-31, the retailer is hosting more than 30 introductory classes across the tri-state area — as part of more than 400 nationwide.

“It’s something that gets back to our mission and belief that a life outside is a life well-lived,” Abramson said. “We’re giving as many people as possible the opportunity to recreate outside.”

Classes held in the city include yoga on the High Line, photography in Brooklyn Bridge Park and a children’s bike riding lesson in Prospect Park.

Throughout the weekend, a camp lounge will also be set up at the High Line’s 14th Street Passage, where visitors can talk to expert guides and get advice on hiking, like how to use a water filter or backpack essentials for a day hike.

Outside the city, activities including stand-up paddleboarding at Glen Island Park in New Rochelle and hiking the Appalachian Trail at Bear Mountain State Park.

Most events have already filled up, though people can sign up for a wait list.