When a man named John Sims made a decision to buy a house in Tucson, Arizona, from a friend of his, he never imagined the purchase would lead to an astonishing discovery.

Once the deal was done, John’s friend mentioned that there was a rumor about the place that there was something mysterious under the ground.

John didn’t give it much thought at the time, but as time passed by, he became more and more interested to unravel the mystery.

He first started exploring the yard by digging four holes on four different sides, but he found nothing. He then thought about it and figured it out that if there was nothing under the grass, there could definitely be something under the bricks. The next step was to take a closer look at municipal records and learn more of when his house had been built. In those records, it said that a company that went by the name Whitaker Pools built a strange structure on the property in 1961. It was now determined that there was indeed something buried there, which made John even more eager to explore the place.

In order to know where to start digging again, he hired consultants with metal detectors. When the detectors began to go off, he was able to mark the spots with Xs.

After he started digging at the marked places, he stumbled upon something metal, but as he couldn’t possibly know what it was, he didn’t proceed. It could be electric wires, a water pipe, or a septic tank, and he didn’t want to take the risk of damaging anything.

In the days that followed, he dug with precision and stumbled upon what looked like an entrance to a hatch. As he bent down, a metal lid opened. But as there was a possibility of gas fumes or mold spores, he left the lid open for a couple of days for the potential gases to waft out and had the air tested for mold.

The following morning, John took a look inside the hatch and found a spiral staircase that was headed downwards.

As a captain of the Rural/Metro Fire Department, he needed someone around in case the lid fell back in, so he gathered a crew. The first thing they decided to do was to repair and reinforce the concrete structure surrounding the stairs and set up Sonotube cardboard around the entrance to ensure that they do not damage anything.

In order to provide proper lighting and in order to be able to use tools, the crew installed an electric line. They also installed a black pipe to funnel fresh air into the shaft.

The work around the structure was done. Now they needed to secure the spiral staircase.

John was the first one to explore the inside of his backyard. Once he reached the bottom, he knew their work was done and they didn’t need to do any more digging. The underground structure was bare, but it was obvious that it represented a nuclear bomb shelter.

The shelter was built during the cold war between USA and the Soviet Union. At the time, the company mentioned above, Whitaker Pools, turned out to expand their business to bomb shelters.

This wasn’t the sole shelter in the area, however.

Tucson was once a rocket town that held 18 ballistic missiles that were capable to travel across continents and destroy an area of 900 square miles. This was a top secret, and with the end of the cold war, the missiles were all disabled.

John’s discovery was of great significance. Once he shared all about it on Reddit, many media outlets were quick to pick up his story.

“I was really hoping it was going to be a little microcosm… a time capsule full of civil-defense boxes, radiation detectors, and cots and stuff like that,” John shared during an interview.

For those around the are who want to know if there is a nuclear shelter in their yard, John suggests looking up records of the City of Tucson or Pima County for information.

In case they do discover anything alike, John urges citizens to be extra cautious, just like he was. “Jumping into holes in the ground is generally not a good idea,” John said and explained that toxic air in a tunnel or a cave-in can easily incapacitate anyone.

It is John’s wish to restore the bomb shelter, but because that requires plenty of money, he set up a GoFundMe page. It is his priority to replace the staircase so that people can enter the shelter easily and explore the place.