Punta de Mita, Nayarit, Mexico - Interest in this small corner of Mexico by one of the world's richest men has helped attract an influx of wealthy investors.

In 2014, Cascade Investment, the private investment firm of Bill Gates, the Microsoft co-founder, bought 19.5 hectares, or 48 acres, of undeveloped beachfront land and the Four Seasons hotel site in Punta Mita, a gated residential resort on the Riviera Nayarit, 40 minutes north of the town of Puerto Vallarta. The cost was reported to be $200 million.

"Bill Gates buying land in the area has had a real impact," said Aaron Fisher, the sales director at Punta Sayulita, another residential development on the Riviera Nayarit. "We needed high-end clients and now they're coming."

The purchase was seen as an endorsement of the region's potential, and the ripple effect has begun to reach surrounding communities. These include Sayulita, a charming, bustling town with a stretch of beach, ideal surf conditions and warren of small streets.

The town has been a draw for watersport enthusiasts and those wanting a more bohemian lifestyle for several decades. But a new wave of cosmopolitan, higher-spending residents has begun to roll in. "Buyers are primarily American, or from Mexico and Canada," Mr. Fisher said. "In particular the Pacific Northwest. There's a big tech contingent but also financiers and media people."

Properties in this region of Mexico are usually priced in United States dollars. Building lots around town are available from $80,000. Small one- or two-bedroom homes start at $130,000, and upmarket two-bedroom apartments in purpose-built blocks start at about $250,000. Hillside villas on large plots with the best views are priced from about $800,000.

Though foreigners cannot directly own property within 30 miles of Mexico's coast, they can buy via a Fideicomiso, in which a property title is held in trust by a bank. Individuals named as beneficiaries of the trust have full ownership rights.

The rise in popularity of the Riviera Nayarit is also driven by the growth of the much larger Pacific coast resort town of Puerto Vallarta as a vacation destination and the expansion of the local airport to allow more international traffic.

In addition to Mr. Gates, executives from tech companies like Apple and Yahoo have also bought property in the area.

What Mr. Gates intends to do with his Punta Mita real estate is not yet known.