Every weekend, hundreds of couples descend on Mexico City's Plaza de la Ciudadela to gently seduce each other in the elegant dance known as danzón. The dancers converge in the pretty square, known locally as the Plaza de Danzón, to dance to classic Cuban melodies in what could be mistaken for a scene from a 1940s film.

In fact, it is part of an extraordinary effort to help danzón thrive in Mexico, while it has effectively vanished in Cuba, where it originated almost 150 years ago. The effort is working, as growing numbers of children and young Mexicans flock to festivals and join classes to learn the elegant steps and dress up in the flamboyant costumes of danzón.

The finest danzón groups from across Mexico recently assembled in the capital to celebrate the 10th anniversary of the acclaimed group Siglo XXI (21st Century). They danced to love songs performed by the Children and Youth orchestra from Oaxaca (Danzonera Infantil y Juvenil de Oaxaca), which with 25 musicians aged between nine and 20 is one of the youngest groups in Mexico.

Danzón is popular in 25 of Mexico's 32 states, with more than 200 registered dance troupes and 20 orchestras.

"Tournaments and galas have increased significantly in the past eight years, which have encouraged people to take an interest in the dance, as well as bringing communities back together in public spaces," said Anaid Chávez of the National Centre for Research and Dissemination of Danzon.

Siglo XXI is led by Armando Sanchez, 43, and Karla Amparo, 24, and the duo are passionate about danzón's charms. Amparo said: "Ten couples from Siglo XXI frequently participate in exhibitions across the country, but we have almost 50 members with students as young as four, five and six who are becoming beautiful dancers, right up to our adored 80- and 85-year-old members. What we have in common is a great love for danzón as an art form."

Amparo's dance partner, Sanchez, attracts youngsters from across the capital to his thrice-weekly classes in the plaza. Sanchez was introduced to danzón as a 16-year-old at Salon Los Angeles, the capital's oldest dance hall, and has been zealously promoting it ever since.

"Forget Cuba, danzón is dead over there, it is now 100% Mexican," said Sanchez. "Danzón is classy, elegant, precise, unique, and each state has its own distinct style. It is strong in Mexico and growing. Just look around at how many people come here each week, it is very much alive."

Like most Latin dances, danzón is as much about style as the steps. The square is filled with pachucos, zoot-suited, flamboyant men who follow the 1940s Latino style that developed in El Paso, Texas, and Ciudad Juárez, Mexico. The classic pachuco look is finished with a fedora sporting a single feather at the back, and a zoot-chain hanging from one trouser pocket.

The women, pachucas or rumberas, wear jaw-dropping high-heels, sparkling makeup and dresses; the purists always dance with a fan to shoo away the heat.

But the styles came much later than the elegant three-step which can be traced back to Matanzas on Cuba's northern shore, in 1870. It was soon introduced into Mexico by traders and refugees of the 10 years' war that began in 1868, arriving through the Caribbean ports of Veracruz and Yucatan.

The father of danzón, Miguel Failde, mixed European and African rhythms to which couples moved gracefully and precisely, gently flirting with each other, storytelling with their bodies. The women, holding a fan or flowers, are dipped and twirled, but with only fleeting touches and eye contact.

In Cuba, it died out as son music and sexier more tactile dances such as mambo, cha cha cha and salsa grew in popularity in the second half of the 20th century. But in Mexico, efforts to save danzón over the past 25 years have paid off. Three Generations, a troupe from Veracruz, were established in 1989 in order to promote danzón among children, at a time when its fate in Mexico seemed sealed with the dying dancehall scene.

It is rarely on the radio or television, so the main advert is the dancers themselves; around half the regulars in Plaza de la Ciudadela are over 60. This attracted Guadalupe Andrade, 78, who started classes last year and is now a regular with her 80-year-old partner.

At the other end of the spectrum, Luis Albarran, 16, is one of the youngest and most stylish pachucos around. He was also inspired by the dancers in the square, and paired up with his older sister to join a troupe at the age of 12. "Our friends are put off by the slow rhythm and old style, but we are different and love everything about danzón," said Albarran. "We don't mind being the young ones, I love learning from the original pachucos."

Chávez added: "Today, danzón is danced in large parts of our territory, in public squares, parks and dance halls, adopted by people of all ages not only as a hobby, but as a lifestyle. The last 20 years has seen a gradual increase in dancers and orchestras, following in the steps of groups like Three Generations in Veracruz, and if this trend continues, there will be danzón for many years more."