The idea of Underground Chattanooga is one of Chattanooga’s best stories. 

You’ve heard the countless anecdotes about vast tunnels, doors that lead to nowhere and windows that open to brick walls. 

And you’ve probably heard something, too, about why Chattanooga’s Underground was created: a raising of the city streets in the downtown area to help prevent flooding following the destructive floods of the late 19th century.

But a new in-depth article released by local history organization Picnooga offers an alternative explanation based on, not surprisingly, photographic research.

“Lost Chattanooga: Underground Chattanooga Uncovered” posits that what many still think was a coordinated effort to raise street levels was, in actuality, the simple architectural evolution of the city over time.

David Moon, founder of Picnooga and author of the article, said for years he’s sought to find photographic evidence of Underground Chattanooga, but in two years of research, what he found instead was evidence of a city that was adapting to the demands of the time.

In April, WTCI released a short documentary called “Underground Revealed” in which they explore several underground locations in Chattanooga. A call to action is issued at the end of the video for the creation of some sort of historical marker or plaque to signify the presence and tell the story of Underground Chattanooga.

Experts were exploring a theory originally offered by UTC archeology professor Dr. Jeff Brown, who first explored the concept of Underground Chattanooga from an academic and historical standpoint. Brown believes in “a long forgotten city beneath the current street level,” and local experts such as Maury Nicely and Nick Honerkamp continue to explore the concept.

Loosely, Brown’s concept is that at some point between 1870 and 1890 local leaders sought to raise the city streets around downtown buildings to prevent future flood damage. In doing so, the first floors of those buildings became basements and so on.

Retaining walls visible in the basement of the Loveman’s Building.(Photo: Staff)

But although Moon has seen evidence of street raising on Market and Broad streets, there is still no evidence (e.g., newspaper articles, fire maps, etc.) to suggest a concerted effort to do so by city leaders at the time.

“There was never a massive effort to bury downtown,” he writes in the article. “I don’t doubt what people see, but I doubt their interpretations. And it’s really hard because you hear all these stories and you don’t see the photos. I believe it needs further explanation. What I’m putting out there is just as much a concept as Brown did.”

But even he’ll agree that his explanation is much less exciting.

Using historical photos as examples, Moon posits that much of what we consider Underground Chattanooga is, simply, an example of “the topography [changing] with the industrial demands of a growing city.”

“It was all about light and ventilation,” he said. “Space was at a premium until about 1920, when high-rises started going up. Up until then, basements were utilized, and in some cases, some of them were constructed half-underground.”

Underground arches at Hub Furniture Co. in downtown Chattanooga. (Photo: Staff)

Moon said it was not unusual at the time to see half-windows for the basements that started at sidewalk level. And many buildings had walk-downs from the street for easy access to the basement levels.

“It was designed that way,” he said. “Then, they would put retail space down there or offices. It was usable space. Eventually, yes, these areas were filled, but they were never public first floors or floors of entry. After searching for two years, I felt comfortable to say it just doesn’t add up.”

By 1915 to 1920, the use of basements became less necessary for business owners, according to Moon.

“Window wells, walk-downs and other exterior entrances were gradually filled in and forgotten,” he writes. “Leveling the city also filled in entrances and windows that fell below grade.”

Regardless, Moon still believes-like others-that Underground Chattanooga is worth exploring. There are still plenty of unanswered questions about the presence of ornate arches in abandoned basements and a mysterious retaining wall underneath the sidewalk between Sixth and Eighth streets.

Moon has looked into hiring an outside research company to do an initial survey on the area, including a study of the retaining wall and arches.

“At least we could pin it down to some possibilities,” he said. “I’m not saying the historians are wrong, but it takes a little more level of expertise to figure out some of the key questions. There’s a lot of possibilities and it’s beyond my experience, which is why I didn’t include those elements in the article.”

Examples of Underground Chattanooga can be seen in several Nooga.com building walkthroughs, such as the Loveman’s Building, Mayfield Annex, Ross Hotel and Hub Furniture Co.