The Gertsacovs might have also sent clippings from ¡Hola! magazine, where the Cartagena wedding party has become a fixture — bullfighters and press barons, politicians and race-car drivers, ex-beauty queens and rising pop stars, all squinting and sweating in the year-round sauna-licious heat. There is also a battle royal of elegant house parties during New Year’s, with owners competing to see who can give the splashiest event for guests from around the world.

Arturo Zavala Haag, a Swiss-Mexican photographer and architect who divides his time between Paris and Mexico City, thinks that the fast-spreading word about Cartagena’s charms will soon make moot any official admonitions. “My two adjectives are ‘architecturally uniform,’ ” he said. “That’s what makes Cartagena such a strangely beautiful place.” When informed that technically he was an adjective short, Zavala Haag took a moment and then complied. “O.K., then, ‘chic.’ ‘Architecturally uniform’ and ‘chic.’ The place is pretty goddamn chic.”

Zavala Haag is correct that conservation of most of the original colonial buildings is one of the city’s allures. The same fortifications that once protected the grandees also forced the neighborhoods of modern Cartagena to grow at a remove from the old city, sparing most of the original structures within the walls from being ripped down in the name of progress. (Good thing, too, as the barrios of Bocagrande and Lagunita, about 15 minutes away by car, are deeply unlovely, with rows of towering apartment buildings.) It’s as if Manhattan below Wall Street had kept its Dutch settlement architecture.

The houses that line the old city’s cobblestone streets give the place a magical ambience. The residences have a distinct Spanish colonial architecture, with tall shutters, thick wood-beamed balconies and stone towers in the back that originally served to spy ships on the horizon. Buildings of similar style can be found throughout Spain’s erstwhile colonial possessions — crumbling to pieces in Old Havana, better preserved in Old San Juan, Puerto Rico, and Veracruz, Mexico. But only Cartagena has hundreds of these elegant edifices in widely varying states of repair, from roofless shells to lovingly restored wonders.

If the old city’s fortifications recall the days of pirates scheming to steal treasure that the Spanish had themselves purloined from all over the Continent, then the dark-skinned faces seen on the streets do as much to remind you that centuries of slave trading also served to fatten the city’s coffers. Cartagena was one of only a few ports on the Spanish Main where the sale and purchase of human beings was permitted. Kidnapped Africans arrived here by the pestilent and overcrowded boatload to travel onward to labor in the silver mines of Peru and the sugar-cane plantations of Panama. (And who do you think built all these impressive fortifications?).

A large cobblestone courtyard near the clock-tower entrance to the old city (now Plaza de Los Coches) was the city’s main slave market, although there is no sign commemorating it as such. The courtyard is now surrounded by raucous bars, and you can sit outside in the evening drinking rum over ice while teenage troupes perform interpretations of traditional African dances to the accompaniment of thundering drums. The rum, the drums, the sea breeze, the dark, flailing limbs of the dancers — it all raises an interesting question of a type pleasure travelers seldom confront: should you really be boozing it up in a defunct slave market?

Sadly, there is little information available in Cartagena about the history of the city’s African population. Only a small section of an exhibit on the history of the city in the Museum of the Inquisition (another of historic Cartagena’s happy institutions) is dedicated to the slave trade.

At the very least, visitors should probably take the time to note how one of the principal legacies of slavery in the modern world — the negative correlation between skin pigment and wealth — has color-coded Cartagena’s old city. Regentrification has resulted in an influx of white faces and a pushing-out of darker-skinned renters. El Centro, which has the most impressive old edifices as well as many of the city’s prominent churches, was the first area to be refurbished. The wealthy Colombians who renovated the old mansions here tend to be fair-skinned, as do the well-heeled guests of the new boutique hotels.

In contrast, there is Getsemani, whose low, small houses for centuries served as the city’s slave quarters. Few affluent Colombians ever venture into this part of town except to visit its dance clubs. There are not many renovated houses or fancy hotels here, but Getsemani has the liveliest streetscape — most evenings it’s like one big block party.

As urban renewal continues and the houses in Getsemani are buffed up into vacation homes and charming inns, the streets of the old city will still very much belong to the descendants of the freed slaves. They are the participants in the chaotic carnival that is quotidian in the developing world, the creative begging, the variably talented performing and the microcommerce of the poor and unemployed: women selling mangos and lulu fruits from baskets balanced on their heads; men hawking individual cigarettes; boys carrying thermoses, offering shots of strong coffee; sidewalk musicians and mimes with their hands out; vendors shilling everything from underpants to auto parts. In this way, the streets are a ubiquitous repository of an Africa-influenced culture and beauty that is one of Cartagena’s greatest assets.

“Without slavery, we would never have had the mixing of cultures, and without the mixing of cultures, we would not have the vallenato, the greatest music in the world,” explained Enrique Santos Calderon, editor in chief of Bogota’s leading daily newspaper, El Tiempo, as we drank whiskey in La Vitrola, a Cuban-themed restaurant in El Centro. Vallenato music, or some derivation of it, is what you hear throughout Cartagena, pouring out of houses and cars, in the restaurants and the dance clubs, where the rich Colombians and their guests frolic. It is the traditional music of Colombia’s Caribbean coast, and although historically the popular music of the poor, it has a passionate following among all Colombians. The music requires three instruments, one from each of the country’s principal cultures. There is the guacharaca (a notched piece of wood stroked with a wire brush) that the indigenous people invented long before they were subdued (read: massacred) by the Spanish conquistadors who arrived here in 1533. The Europeans contributed the accordion, and with the slave trades came the caja, a small drum.
Late at night, the old city emits a melancholy vibe of European grandeur transported to this new continent but ultimately abandoned to molder in the tropical heat. After Cartagena’s founding, the city’s elite, descendants of the original soldiers and merchants, were eager for it to attain culture to match its wealth. Theaters were built and operas performed. Universities were founded, and the latest books and fashions were imported from across the ocean — everything came first to Cartagena before being transported to the rest of South America.