There are a few different “Playas Naranjo” in Costa Rica but the most notable is the arcing crescent of golden sand facing witch’s rock (roca bruja) along the northwest edge of the Golfo de Papagayo Guanacaste.

Naranjo Beach, Playa Naranjo - View towards Witch's rock in the Golfo de Papagayo Guanacaste, Costa Rica
The Pacific swell angles in past Witch’s rock and creates a wave that’s legendary among surfers and was featured in the cult classic film Endless Summer II. The campground can get surprisingly crowded when the surf is up, but if you’re seeking solitude there are dozens of kilometers of trails in Santa Rosa National Park and some lead to even remoter beaches like Nancite where it’s unlikely you’ll ever meet another person.
The campground at Naranjo is a few meters off the beach under scrubby trees and offers grills, picnic tables, pit toilets, and flat sandy spots to pitch a tent. There are brackish water showers to rinse off the salt spray, but the is NO fresh drinking water available.
A two stage shelter system is a good idea. You’ll want a lightweight tent or hammock with mosquito netting to keep the mosquitoes at bay and a large light weight tarp you can string from the trees six or eight feet up to keep the rain and sun off. Keep your food in tough sealed containers or strung up with thin cord at least six feet off the ground and away from the nearest branches.
We had to leave a day early after the mapaches (shrimp eating raccoons) made off with one of our food bags in the middle of the night. I swear the little buggers had a plan and worked as a team.

Pizote and mapaches will raid your camp and haul off anything that's not nailed down.
We’d gotten lazy and dove in the tent leaving a food bag on the picnic table when an evening thundershower hit. About 1:00 a.m. we heard scuffling out in camp and I got out with a flashlight to see a couple pair of beady eyes look back at me before the coons scooted off. I couldn’t tell if they had our supplies so I chased them through the scrub and out onto the beach, but I had been set up. While I was off chasing the diversion the rest of the raccoon team moved into camp and cleared out everything that wasn’t nailed down.
In the daylight we found our scattered gear and the empty wrappers and bags from our provisions about fifty yards away.
Pizotes (coatamundi) also live in the area.