On a tip from Nick Blomstrand, one of the students from Unit 11 at the Bartlett School of Architecture, with whom Venue had the pleasure of traveling through Florida for a week while they did research for their various design projects, we stopped by the former hollow-earth cult settlement—and now state historic site—in the purpose-built town of Estero.

Estero was founded in 1894 by Dr. Cyrus Reed Teed, who, following a spiritual awakening, renamed himself Koresh. The National Park Service (PDF) describes Estero as "a 19th-century post-Christian communistic utopian community."

The meandering but precisely designed network of paths laid down to connect buildings on the coastal site were all paved with hundreds of thousands of seashells so that the walkways could reflect moonlight, a geometric garden illuminated by the sky.

One of the central beliefs of the Koreshan community was that human beings live on the convex inner surface of a vast hollow sphere, with the sun and stars all burning inside, at a central point around which the surface of the earth is wrapped.

Image courtesy of the Koreshan Unity Collection of the Florida Memory Blog.

To demonstrate the concept, Koresh produced several small models: globes within globes that he then took with him to various fairs and public lectures, seeking to find (or to convert) fellow planetary free-thinkers.

Dr. Cyrus Teed and his hollow-earth globes at the Pan American Expo in Buffalo, New York, 1901; image courtesy of the Koreshan Unity Collection of the Florida Memory Blog.

As it happens, hollow earth cults were not, in fact, entirely uncommon for the era—Jules Verne's classic science fiction novel Journey to the Center of the Earth, for example, exhibits tinges of hollow earth thinking and even Edgar Allan Poe's "Descent into the Maelstrom" was influenced by ideas of a hollow earth with hidden entrances, amidst great and dangerous landscapes, at the earth's poles.

Indeed, as David Standish writes in his book Hollow Earth: The Long and Curious History of Imagining Strange Lands, Fantastical Creatures, Advanced Civilizations, and Marvelous Machines Below the Earth's Surface, it was Sir Edmund Halley, of Halley's Comet, who "gave us our first scientific theory of the hollow earth—in his formulation, consisting of independently turning concentric spheres down there, one side the other. Halley arrived at this notion, which he presented to the prestigious Royal Society of London, to account for observed variations in the earth's magnetic poles. His true imaginative leap, however, lay in the additional thought that these interior spheres were lit with some sort of glowing luminosity, and they they might well be able to support life. Generations of science fiction writers"—not to mention "communistic" utopians—"have been thankful to him for this ever since."

However, the Koreshan community at Estero sought to make good on the spiritual-scientific promise of these theories by taking them one step further into the realm of empirical testing and experimentation. That is, they attempted to prove, by way of homemade geodetic instrumentation and other landscape survey tools, that the earth is hollow and that, as they describe it, "we live inside."

Image courtesy of the Koreshan Unity Collection of the Florida Memory Blog.

Enter the so-called Rectilineator, a massive measuring rod—or, as science writer Frank Swain joked recently at a talk in Amsterdam, "a really big ruler"—that could be easily assembled and disassembled in large modular sections. Thus advancing down the smooth sloping beaches of south Florida, the Rectilineator would gradually do one of two things: either 1) it would depart from the earth's surface, thus proving that the earth, alas, was the way everyone else said it was and that we lived on the outside of a concave sphere, or 2) it would move closer and closer to the earth's surface, thus proving, on the contrary, that the Koreshans were correct and that the earth's surface was convex, slowly curving up into the sky, thus proving that we live inside a hollow earth.

The Rectilineator in action.

It should not come as a surprise to learn that the Koreshan beach survey of 1897 "proved" that the earth was hollow, thus vindicating Dr. Cyrus Teed in the eyes of the people who had followed him to what was, at the time, a subtropical backwater in a thinly populated state.

A module from the Rectilineator; image courtesy of the Koreshan Unity Collection of the Florida Memory Blog.

Things went downhill, so to speak, from there. After an ill-advised step into local politics, and a disastrous miscommunication with the local police force, Dr. Cyrus Teed was beaten to death, his theorized resurrection never came, and the cult slowly disbanded, leaving their settlement behind, intact, a town full of pseudo-scientific surveying tools abandoned to the swamp.

In 1976, what remained of the site was cleaned up and added to the National Register of Historic Places, becoming the Koreshan Unity Settlement Historic District. You can now visit the site—located alarmingly close to a freeway—and walk the shell-paved paths, wandering from cottage to cottage past a number of small historic displays, trying to tune out the sounds of passing cars.

Briefly, the aforementioned science writer Frank Swain, while discussing the Koreshan Unity settlement and the Rectilineator they used to measure the curving earth, provocatively compared their survey tools to NASA's so-called LISA satellite mission, which is, in Swain's words, also "a really big ruler" in space.

The LISA mission, more specifically, will use three laser-connected satellites placed five million kilometers apart in deep space to measure gravitational waves and the warp & weft of spacetime itself—a kind of Rectilineator amidst the stars, proving or disproving whatever theories we care to throw at it.