Lerma Marshes (San Miguel Almaya)

A supernatural siren lives in these wetlands; men who fall for her beauty are never seen again.

The Lerma marshes and the lagoon of San Miguel Almaya lie in the Mexican state of México, beneath the dormant Nevado de Toluca volcano. More than eleven thousand years old, these bogs gave rise to the dark legend of Tlanchana—a supernatural being whose very name has spelled death for centuries.

“Tlanchana” comes from Nahuatl and roughly means “Woman of the Earth,” reflecting her complete dominion over the swamp. To the Otomi she was originally known as Acapaxapo, a kindly oracle people consulted about the future. After the Aztecs arrived her image merged with their own fearsome chaos deities, turning the once-benevolent spirit into a vengeful, destructive force.

Pre-Hispanic Tlanchana looked nothing like the European mermaids most of us picture. Chroniclers described her as a towering, dark-skinned figure whose lower body was the writhing coils of a gigantic black serpent—a symbol of chthonic power. Though naked, she wore lavish ornaments: a gleaming crown and a belt strung with live fish and crayfish. Tlanchana’s hallmark was shape-shifting. In anger she kept the serpent’s tail; in a calmer mood it became a fish tail; and when she wished to walk on land, it turned into human legs.

The curse of the San Miguel Almaya wetlands is the result of a fatal clash between people and this fiercely territorial spirit. Tlanchana rarely leaves the depths, lurking behind thick stands of reeds. Her hypnotic beauty can break any mortal man’s will, and disappearances follow one of two scripts. If she is hunting, she gives herself legs, steps ashore, charms her victim, and leads him into deep water to drown. Should a man resist, she instantly takes the form of a giant snake, coils around him, crushes his bones, and drags him under.

Local ecology grounds the legend in grim reality. The Lerma bogs hide real hazards: dense fog, sucking mud, and pockets of flammable methane. Disorientation from marsh gas—or a lone death in quickmire—was long blamed on Tlanchana’s malice. Before germ theory, fevers contracted after a visit to the lagoon were likewise called her curse.

To fend off her spells, villagers carry a freshly cut tule reed. The plant serves as a sympathetic charm, a token of one’s right to walk the marsh.

From 100 Cursed Places · Fern Flower Press