A massive hole, about 25 feet deep, opened up in the front yard of a Colorado Springs home.

The family living in the house in the Broadmoor area thinks the hole was built in the 1950's along with the house.

The Garvens family is lucky no one was hurt when the ground caved in. Their kids often play in a tree where their dad built a small fort, the hole is just feet away. "If you stand over it, it actually makes you dizzy,” said Jay Garvens. “I mean it is gigantic."

A temporary orange fence circles around the gaping hole. The fence was put up by a neighbor, before he went and told the Garvens about the hole.

"It just caved in, no one saw it, we didn't hear it," Jay said.

Jay and Marlo Garvens’ 6-year-old son spotted the opening. "He just said, 'whoa mommy did you see that hole?' and i just kinda looked and i saw some of the dirt and i knew there was a hole," said Marlo Garvens.

Inside the hole is scarred cinder block from a rusted pipe. The broken pipe, Jay believes, is partly to blame for the ground collapsing.

Inside, the hole is lined with cinder block. "To see the bricks and everything, I'm like, well this is really strange," said Marlo.

The hole, which likely sat empty for 50 years, is now partially filled with splintered wood planks, snapped pipes, dirt and snow.

"We would love to find out what it was," said Marlo.

So far, suggestions have been anything from prohibition storage, the foundation for a silo, a septic tank, a cesspool, and a bomb shelter.

The family here already talked with city officials. They say it can't be the city's because there were no city utility or sewer services out here in the 50's.

Jay says he doesn't want to do anything with this until he knows what it was so he can decide to fill it or restore it. Current estimates put the cost of building a 25-foot underground structure like this at $20,000 in today's money.

If you have any information on what this hole may be, please email your conatct information to the reporter, Rick Montanez, at RMontanez@kktv.com