Locals say it's rumored to be haunted.
Built in the early 1900's the Bowen Building cared for patients across the state deemed unfit to live alone.
Researchers say hundreds died within its walls.
"We feel like their souls have just not passed on, not gone where they're supposed to be," said Krystal Depew.
Depew is the Chief Executive Officer of the Illinois Ghost Seekers.
She claims to have encountered dozens of spirits, and is eager to explore this property for the first time.
"We've been waiting and waiting and waiting, so we're very excited."
Depew and her team believe there is a paranormal presence in the building.
So WMBD-31 tagged along, armed with special devices to pick up extra excitement in the air.
"They have electromagnetic energy that sometimes manifests and anybody can feel that," Depew explained.
We visited the autopsy room in the asylum basement.
It happened to be strangely cold.
"We were downstairs already hearing noises," laughed Depew.
While we didn't encounter ghosts directly on our tour downstairs...the researchers aren't giving up hope.
"I think the fact that we cater to the historical part and the paranormal part, it just gives a little bit for everybody," said building co-owner Trish Weiss.
With lots of history behind these rumored haunted halls, the group hopes more people take part in a paranormal experience.
Just in time for Halloween, the Bowen Building is offering public tours on Friday and Saturday nights.
Log onto www.peoria-asylum.com for more information.
In the long run, owners plan to convert it into a bed and breakfast.