Like parts of Okinawa, Armenia, Sardinia and a handful of other blessed places, the picturesque Nicoya Peninsula in the Central American nation of Costa Rica boasts one of the highest human longevity rates in the world.

It is not at all unusual for the residents of Nicoya to reach the ages of 90, 100, even 110.

Located on the northwestern part of Costa Rica, just south of the Nicaraguan border, the Nicoya Peninsula (about 80 miles long and 30 miles wide) is a pristine land of beaches, upscale resorts, woody hills, cattle ranches and cow pastures. ABC News reported that most of the 75,000 people who live here work as farmers, laborers or cowboys -- much like they have for centuries at a leisurely pace.

Nicoya is also the driest part of the country and rather isolated.

Dan Buettner, an author who has studied so-called blue zones around the world (that is, regions where centenarians are common) told National Geographic News that the secret to living long lives appears to be related to eating a plant-based diet, maintaining regular, low-intensity activity and keeping close to friends and family.

"A 60-year-old in Costa Rica has more than a four-fold better chance of making it to 90 than a 60-year-old in America," he told National Geographic.

"[The Costa Rican government] spend one-fifteenth the amount we do on public health, but they spend it in the right places."

Costa Ricans as a whole have the lowest rates of middle-age mortality in the world and the second-highest convergence of males age 100 or above. Out of a total population of about 4.5 million as of June, 417 Costa Rican centenarians were reported, many of them in Nicoya.

According to the CIA World Factbook, the average life expectancy in Costa Rica is about 78 years -- comparable to the U.S. and European Union.

Buettner initially went to Costa Rica to back up research by local demographer Dr. Luis Rosero-Bixby suggesting that Costa Ricans enjoyed high life expectancies as well as very low cancer rates.

Rosero-Bixby, of the Universidad de Costa Rica, wrote that elderly Costa Ricans have a reduced incidence of cardiovascular diseases and a low prevalence of obesity.

So, what’s their secret?

Buettner’s subsequent research discovered that Nicoya’s local waters are unusually rich in calcium and magnesium, which strengthen bones and muscles.

The local folk also have a deep faith in God, sleep eight hours a night and maintain a healthy diet filled with rice, corn, plantain, beans and strange fruits like the vitamin-C-rich orange-like maroñon, the pear-like anona and chayote, a squash-like vegetable.

They also do not overeat nor do they consume too much red meat.

In a broader context, Costa Rica represents an idyllic oasis of peace and stability in a region otherwise battered by poverty and civil wars.

Indeed, Costa Rica enjoys a well-developed social welfare system, possesses no standing army (having abolished it in 1948) and high living standards.

“For more than 190 years, Ticos [Costa Ricans] have enjoyed the benefits of a democratic government, making it one of the oldest democracies in the world,” wrote Kat Sunlove, an American retiree in Costa Rica and blogger.

“Over the course of those two centuries, enlightened leaders have promulgated social and economic reforms that have resulted in a country with an outstanding -- if still imperfect -- social welfare program, health care system, commitment to conservation, educational system and a large land-owning middle class.”

Costa Rica's political stability rests on its decision to abolish its army after its 1940s Civil War, Jamie Chandler, a political scientist at Hunter College in New York, commented.

“There's no threat of military coups and no gray areas between the role of generals and elected officials that could undermine the common good,” he said.

In addition, Costa Rica also has had decades of strong economic growth that has attracted significant amounts of foreign investment.

”Its GDP grows about 2 percent year,” Chandler noted.

“Exports have tripled since the 1980s, and its tourism industry is a cash cow.”

It is for good reason that Costa Rica is often referred to as the Switzerland of Central America.