There was one other critical ingredient that Mr. Johnson found here: Susan Short, a naturalist, filmmaker and also a surfer, whom he met on one of his early visits to Nosara and who is now his wife and partner in their business endeavors.

The couple have gone on something of a buying spree in town, purchasing two small hotels; two unfinished condo developments; and even the local weekly newspaper. They are determined to prevent large-scale, resort tourism from taking hold, and have enough available capital to actually stop it.

Image One of the hundreds of thousands of Olive Ridley sea turtles that breed on Playa Ostional from July to early December. Credit Toh Gouttenoire for The New York Times

The centerpiece of this effort, at least so far, is the 24-room Harmony Hotel, which has the aura of a Lana Del Rey music video — with its 1950s-era tropical décor, its super-attractive, super-fit clientele, its juice bar and healing center with classes like Yin & Yoga Nidra.

The Harmony is not a place that pampers its guests, despite the premium price: The rooms are relatively small and hardly luxurious (and lack televisions), and room service is not offered. (Rates range from $210 for a basic room in low season to $990 a night for a two-bedroom bungalow over the Christmas holiday.) Mr. Johnson is proud of the fact that it serves no sugary sodas or junk food. Even the minibar is stocked with treats like a homemade granola bar and artisanal chocolate.

It is just what the regulars come for. In this unpretentious beachside spot, the lobby at times seems more like a family room. Children hang out while their parents are at the pool or dining on plates like ceviche and Costa Rican casado in the nearby bar and open-air restaurant.

A lush, tropical garden connects the hotel lobby to the nearby bungalows — serving as home to howler monkeys, hummingbirds and other wildlife — and the hotel’s yoga center, day spa and juice bar. Mr. Johnson is going to open an organic supermarket nearby soon.

The hotel does no advertising outside Mr. Johnson’s website, yet it has become an impromptu gathering place, particularly during the peak season, of filmmakers, fashion designers, journalists, Silicon Valley tech executives and New York bankers, their spouses, and children, as well as a sprinkling of European families who somehow heard about the place. Almost all of them know Mr. Johnson or his wife personally, or someone else who does.