Cartagena

Colombia

In 1697, a French privateer named Jean-Bernard Desjeans stood on the deck of his ship, staring at the most formidable set of city walls in the Americas. After a month-long siege of Cartagena de Indias, with his fleet reduced by disease and cannon fire, he gave the order to withdraw. The Spanish defenders, watching from the ramparts of the San Felipe de Barajas fortress, had been outnumbered nearly three-to-one. They did not win the battle through force of arms, but through geography. The city’s defenders had opened the sluice gates of the Zanja de la Matuna, a man-made canal, flooding the lowland approaches to the fortress and turning the land into an impassable swamp. The land, engineered for defense, had fought for them.

Cartagena exists on a fragment of the South American continent, a hooked peninsula and a cluster of low islands separated from the mainland by a labyrinth of shallow bays, lagoons, and mangrove swamps. To the west, the open Caribbean presents a highway for ships and a threat from pirates and rival empires. To the east and south, the maze of the Bahía de Cartagena and the Ciénaga de la Virgen creates a natural moat. The indigenous Kalamarí people, part of the broader Cariban-speaking groups, understood this amphibious landscape. Their name for their settlement, Kalamarí, likely meant "crab," an apt descriptor for a community living between sea and lagoon, on land that was more a collection of islets than a solid plain. They fished the bays and navigated the waterways in dugout canoes, a way of life dictated by the water that surrounded them.

The Spanish, arriving in 1533 under Pedro de Heredia, saw the same geography through a different lens. The water was not just a source of food but a barrier. The deep, calm anchorage of the bay was a perfect harbor for the galleons of the Spanish treasure fleet. The narrow, easily defended entrance at Boca Chica (Little Mouth) could be sealed with a chain boom and covered by artillery. The islands and the peninsula were defensible positions. Heredia founded his city on the southern shore of the peninsula, facing the bay, deliberately turning its back to the open sea. The initial settlement was a statement of intent: this would be a fortified warehouse, a vault for the wealth of a continent. Gold and emeralds from the New Kingdom of Granada (modern Colombia) and silver from Peru were carried overland and down the Magdalena River, then shipped along the coast to be stored in Cartagena’s royal coffers until the annual fleet arrived from Spain. The city’s sole reason for being was to concentrate this portable wealth and protect it.

This function made Cartagena a target. The response, over two centuries, was the most extensive program of military engineering in the Western Hemisphere. The conversation between the land and its inhabitants became one of concrete, coral stone, and geometry. Beginning in the late 16th century, Italian and Spanish engineers designed a system that treated the city itself as a castle. They enclosed the entire urban core, El Centro, within Las Murallas—thick, squat walls designed to absorb cannon shot. They built a series of independent forts: San Fernando on one side of the Boca Chica strait, San José on the other, so crossfire could obliterate any ship trying to force the channel. On the hill of San Lázaro, overlooking the only dry-land approach from the mainland, they constructed the Castillo de San Felipe de Barajas, a sprawling, polygonal fortress with overlapping fields of fire, underground galleries for counter-mining, and cisterns for sieges. The crown spent amounts that were staggering for the era, an estimated 10 to 12 million pesos over two centuries, because the loss of Cartagena meant the collapse of the Spanish financial system in the New World. The land, a mix of soft sand and hard coral rock, was both a challenge to build upon and a source of material; the walls and forts are built from coquina, a sedimentary rock formed from fossilized coral and shells, quarried from the very islands the city occupies.

The human geography within the walls was a stratified mirror of the colonial economy. The wealthy merchant and official class lived in large, single-story houses with internal courtyards for cooling, their thick walls painted in ochers and yellows to reflect the sun. The city’s need for labor, for dockworkers, artisans, and domestic servants, was met by the transatlantic slave trade. Cartagena was one of two authorized slave ports in Spanish South America. From the early 17th century, thousands of enslaved Africans passed through the Customs House and were sold in the Plaza de los Coches. The city’s demographics transformed; by the 1770s, people of African descent—both enslaved and free—constituted more than half the population. Their cultural and spiritual resistance shaped the city. In the district of Getsemaní, across a small bridge from the wealthy center, a free Black militia was formed in the 17th century. The syncretic religious practices that developed, blending Catholic saints with African deities, survive in neighborhoods like San Diego and La Matuna.

The city’s strategic purpose ended abruptly in the early 19th century. The wars of independence, culminating in Simón Bolívar’s victory in 1821, severed the tie to Spain. The decline of the gold and silver economy, and the silting of the Dique Canal that connected Cartagena to the Magdalena River, left the city isolated. For over a century, it languished as a provincial backwater, its population shrinking, its magnificent walls crumbling. The thick walls, designed to keep enemies out, now stifled growth and modern circulation. The economy reverted to a smaller, regional scale: fishing from the bays, small-scale cattle ranching on the mainland, and shipping tropical hardwoods from the mangrove forests it had once seen only as a defensive buffer.

Cartagena’s modern revival began in the early 20th century, triggered by a new geographical imperative: petroleum. The discovery of oil in the Magdalena River Valley in the 1910s and 1920s required a deep-water port for export. Engineers dredged the Bocagrande channel and constructed the Mamonal industrial zone on the mainland shores of the bay. The city expanded beyond its walls for the first time in a substantive way, with the thin peninsula of Bocagrande being developed with high-rise hotels and apartments in the 1950s and 60s, mimicking Miami. This new growth created a stark physical divide: the preserved, colonial "museum" city within the walls, and the sprawling, modern city of concrete and traffic outside them.

Today, the conversation between land and people is defined by tourism and climate. The historic walled city and Getsemaní, named a UNESCO World Heritage Site in 1984, are preserved not for defense but for visitor consumption. The same features that defined the colonial city—narrow, shaded streets, secluded courtyards, massive walls—now provide a picturesque pedestrian experience. The Bazurto Market on the mainland outskirts operates as the chaotic, vital supply hub the old city can no longer accommodate. The city’s location, once its greatest asset, now poses its greatest threat. Cartagena is intensely vulnerable to sea-level rise. Much of the city, including the historic districts, lies at or barely above sea level. Chronic flooding during high tides and storms is already a routine occurrence, with seawater bubbling up through drains in the Plaza de la Aduana. The defensive moats of the ciénagas are now flood zones that inundate impoverished neighborhoods like Pie de la Popa built on their unstable shores. The engineering challenge of the 21st century is no longer keeping enemies out, but keeping the ocean at bay.

The logic of the place remains, however, in its oldest stories. In the neighborhood of La Popa, atop the 150-meter-high hill that gives the district its name, stands the Convento de la Santa Cruz. According to local legend, the hill was originally called La Popa del Galeno (The Galleon’s Stern) for its shape. A more persistent folktale, dating to the colonial era, tells of a mysterious, fragrant basil plant that would appear on the barren hilltop. A monk, following the scent, found the plant and built a hermitage. The faithful believed the plant was placed there by the Virgin Mary to ward off the devil, who was said to reside in a cave on the hill. The story is a spiritual map of the early colonial mind: a sacred scent colonizing a pagan landscape, a monastic fortress mirroring the military ones below, asserting a divine order over a geography that was, for the Spanish, both perilous and providential. It is a reminder that the first response to a new land is often to tell a story about it, to name its hills and blame its shadows, long before the first stone of a wall is laid.