Man Discovers Sprawling Tunnel System Filled With Bats Below His New Home

A homeowner discovered a sprawling tunnel system beneath his new house, filled with bats.

Guido, posting under the name NetAtraX on Reddit, bought the home in southern Italy, around 18 miles outside Rome.

He snapped up the six-bed, two-bathroom house with a balcony in October 2020, and had no idea how deep the tunnels went, after the listing only described them as storage. A deed plan refers to them as the "grotto tinello," which translates into dining room.

Guido finally managed to explore part of the three-level subterranean system, and shared a video to Reddit on Monday as he captured the vast space.

He told Newsweek: "It is a bit creepy going down there, and it seems as if the previous owners only put some jars on the stairway leading down, but never dared to explore the whole system. Also in old plans of the house, they only write about 'storage facility,' without mentioning how big these tunnels really are."

Detailing the layout of the plot, which is more than 1,000 square meters (over 10,000 square feet), he explained there's a main house and a newer, smaller structure next to it, connected to the barn where he found the tunnel entrance.

"Around the house are olive trees, some more than 100 years old. According to old plans, there were also many lemon trees. Part of the land is wood, part is a vineyard, part grass, part olives," he explained.

In the Reddit post, he wrote: "While the entrance seems to be newer, the tunnels literally are carved out by hand. It is cold in the tunnel, humidity is 99%, and there are some alcoves all a couple of meters."

He was able to enlist the help of a friend to help him explore the second level, as he continued: "I was able to go down to the second underground floor. Going down, the tunnel is first only about 1.6 meters high. It gets about six meters down, then there is a pond. There, the tunnel opens up and is about 2.5 meters high, two or three meters wide. It makes a turn to the left.

The tunnel system under Italian house
Photo of the sprawling tunnel system under an Italian house. Guido bought the house in October, with the property featuring six bedrooms, two bathrooms and a balcony. NetAtraX/Guido

"In this turn, there is another stair going down another 8 meters before turning to the right. There was no way to go down there with the equipment I had (and, to be honest: lack of courage).

"After the curve, the tunnel continues. I walked about 10 meters, then parts of the ceiling has collapsed. This must be at the place where my house is. In the light of my torch, I saw that the tunnel continues further than I could see.

"Also explored the first floor. Lots of bats, two—obviously newer—air shafts. But still no hint as for what it could have been used."

Guido confirmed he's bought a drone to explore the unstable parts of the tunnel, saying: "I bought a drone with a camera and will try to fly it to places in the system where I can't go to or where I don't have the heart to go to. In the second underground floor, huge parts of the ceiling collapsed. I haven't made a plan of the tunnel system, but it seems as if this is the part below my house. I want to drive the drone through this part as well as down to the third underground floor which is about 20, 25 meters below the surface."

Despite doing some research, he confirmed nobody has been able to tell him what the caves were used for. "One guy said the tunnels were part of a subterranean aqueduct. There are at least three levels of tunnels, and they do not seem very practical for storing wine," he mused.

But he came up with some theories after speaking to neighbors, saying: "I asked a lot of locals, and all [they] came up with other explanations, like for wine, for sausages, for hiding during the war. But all these explanations do not add up. For wine, it is too humid. And it wouldn't make sense to dig at least three floors down into the ground. For food the same.

"Hiding could be, for the house is not too far away from Anzio where the US troops landed during WW2 for liberating Italy from the fascists. However, the way the tunnels were dug leave the impression that they are much older.

Photo of the tunnel system in Italy.
Photo of the tunnel system in Italy. NetAtraX has bought a drone to explore deeper into the tunnel, including parts which have collapsed. NetAtraX/Guido

"I learned that there are many more such tunnels in the area, and in one paper I read that they could have been used for transporting water, although I still don't fully understand how this should have been done. Still trying to get in contact with experts who could shed some light on this."

Newsweek agreed to only use Guido's first name, although his identity was verified. He confirmed that he has plans to install machinery to extract moisture from the humid air in the tunnels, and use it to water his olive trees.

The post, shared on Monday, has already amassed more than 6,000 comments, as Solid-snake88 said: "Have you never seen any movies? Clearly those tunnels lead to the gates of hell."

Shiafisher wrote: "Either a wine cellar or Batcave."

Nonick96 commented: "WW2 bunker maybe?"

While Digifork warned: "This right here. NEVER enter a void space without testing for breathable air. It only takes moments in an oxygen devoid space for you to pass out."