WATCH: Family Opens the Rusty Old Hatch In Their Backyard and Never Expected to Find This Inside

A Wisconsin family made an unexpected discovery dating back to the Cold War, right in their own backyard.

Ken Zwick and Carol Hollar-Zwick say they bought their home in 1999. It came complete with a mysterious rusty hatch in the ground. They said they knew it led to a Cold War-era fallout shelter, but for years they assumed it was empty so they never opened the hatch.

Up until 2010, that is. They finally cleared out the overgrowth and opened up the hatch.

Inside they found five-feet of water, with watertight Army supply boxes floating on the surface.

The boxes contents turned out to be a remarkable time capsule, and enough supplies to last a family about two weeks in hiding.

“It was all of what you would expect to find in a 1960’s fallout shelter,” the family told local news outlets at the time of the discovery.

Fallout shelters were popular in the 1960’s United States, when Americans and Russians danced in threat of war. The shelters were meant to protect the inhabitants from atomic fallout.

According to reports, the Zwicks chose to donate their findings to the Neenah Historical Society for preservation.

See inside their discovery in the video clip above.