Few of the customers who flock to City Market to eat or shop know the history of the place, it dates all the way back to the 19th century.
Even fewer realize that there's a mystery that rests far beneath City Market in a place that is off limits and unknown to everyone who visits.
"It’s a tremendous place down here. It's so unique," Jim Reilly said.
Down the stairs and behind a locked door, you'll find the passage to the dark, mysterious place that has no official name.
It's a series of catacombs that cover more than 20,000 square feet under the downtown streets.
It's filled with brick archways and chambers the size of meeting rooms but no one knows why it was built.
"I’m very curious to know what went on down here on a daily basis, why it was built so big with so much time and workmanship. It doesn't make a whole lot of sense to me," Reilly said.
Jim Reilly is the executive director of city market and the unofficial caretaker of the downtown catacombs.
"Wow, wow is the most used word," he said.
He sometimes gives tours but even after years of visiting and research, he said he's still amazed at what you can find in the catacombs.
"Something as small as a bracket or a hook or old rails, there's always something new that raises questions about what went on down here," he said.
Reilly said the catacombs were built in 1885 and served as the basement of Tomilinson Hall. Tomilinson was the Conseco Fieldhouse of its time in Indianapolis.
An archway downtown is all that's left above ground of the structure after it burned down in 1958.
The huge limestone supports of the building remain underground complete with notches leftover from the dynamite that blasted it out of an Indiana quarry.
"Ship it up here, put it in this pit, think about it 1883-1884."
Old wires, pipes, pieces of wood - all litter the dirt floor.
"When you go through the catacombs you find pieces of history. No one knows what this old utility cart was used for so long ago."
"We just don't know what happened down here. It raises more questions than it answers," he said.
There have been those who wanted to develop this space. They wanted to turn it into a nightclub or a wine bar, even a restaurant.
"Do you do one large restaurant? Or four five smaller ones?"
Every idea has proven too expensive or too impractical which means the future of the catacombs is just as uncertain as its past.
Unlike the City Market, it is not protected as an historical landmark. If a developer builds on the property above, they could bury this space and seal all its history and all its mystery away forever.
"It’s history, you lose history," Reilly said, "you lose part of old Indianapolis."
