Issued on February 16, 2024
Wetlands in eastern England harbor a wealth of eerie tales that send shivers down the spine.
The ethereal glow of the will o’ the wisp; the infamous Black Shuck dog lurking in the mist; mysterious circles where fairies cavort, witchcraft holds sway, and only the foolish dare to tread—stories from the area are fraught with supernatural dangers.
Even in modern times, the 1,500 square miles of wetlands in this region, stretching from the icy touch of the North Sea to the towers of Cambridge, become desolate once night falls. It’s all too easy to find oneself engulfed in putrid water or ensnared in a quagmire of thick, dark mud.
The locals refer to these eerie landscapes as The Fens. Similar wetlands exist worldwide, each with a slightly different moniker. Bogs and fens (with bogs being more acidic) are formed in depressions left by retreating glaciers during the last ice age, now filled with decomposing plant matter known as peat. This layer is often covered by sphagnum moss, giving the ground a spongy and treacherous quality. Marshes, on the other hand, are waterlogged regions near rivers and coastlines, featuring reeds and soft-stemmed shrubs. Swap these herbaceous plants with woody stumps and trees, and you have a swamp.
No matter their classification, these realms serve as fertile ground for our spectral folklore.
Mysterious Phenomena in the Haze
Fog poses as one of the most formidable hazards in a bog.
“When there’s enough moisture in the air, condensation occurs on aerosol particles,” explains Nadine Borduas-Dedekind, an atmospheric chemist at the University of British Columbia, Canada. “In the Arctic, fog is rare due to the sparse particles in the air. However, in a swamp, there is a presence of biogenic material and water droplets.”
The primary contributors to this fog are volatile organic compounds—tiny particles emitted by plants that quickly evaporate. These compounds, as Borduas-Dedekind describes, undergo oxidation in the atmosphere, leading to the formation of larger molecules that readily absorb water and develop into clouds.
The timing of this process plays a crucial role in the wetland’s mystical illusions.
As the sun goes down, the Earth’s surface cools, causing the air to become denser and boost relative humidity, resulting in condensation of more water vapor. This gives rise to radiation fog, a dense, low-lying cloud typically appearing late at night or just before dawn—precisely when our weary minds are more prone to perceive shapes in the darkness. It’s no surprise that the great detective Sherlock Holmes confronted the menacing Hound of the Baskervilles amidst the night-time mists of a bog.
Therefore, it’s not unexpected that another supernatural entity in wetlands capitalizes on our unease in the dark. Will o’ the wisp—known as ignis fatuus, jack-o’-lantern, or fool’s light—are phantom lights believed to entice travelers away from safe paths through bogs and lure them into an abyss from which they never return.