When it comes to Missouri, the list of places that are thought to be haunted, and worth visiting, is endless. There's one spooky place that stands out from most, and that's the Missouri State Penitentiary. This haunted and now decommissioned prison in Jefferson City is claimed to be home to many spirits that committed serious crimes while alive from 1836 to 2004.

The Missouri State Penitentiary operated from 1836 to 2004, during which it earned the title of "oldest continually operating prison west of the Mississippi."

A penitentiary, as many know, is a prison for people who have been convicted of very serious crimes. Using your imagination, it's easy to picture what the prisoners who wound up at the penitentiary did to get there.

This, combined with its age, makes for a hotbed of paranormal activity at the Missouri State Penitentiary. It's even been explored by TV's Ghost Hunters.

If that's not a serious sign of its eeriness, then we don't know what is. With 40 inmates put to death in the gas chamber between 1937 and 1989, some never even left.

Now, numerous tours are offered to give visitors the chance to experience the otherworldly side of the prison. You can spend hours, or even an entire night, exploring the place where some of Missouri's most crooked criminals died.

You can find endless unsettling photos of the Missouri State Penitentiary across the internet. A quick look at photos of the inside will make you feel as though you're there.

According to this photo's caption, the prison offers "guide-led photography tours for those interested in capturing the architectural beauty of the historic site."

Who knows what (or who) you'll be able to capture if you embark on one of their tours.

You can tell just from these gates pictured above that this prison wasn't a particularly pleasant place for prisoners to spend the night in.

A visit to this penitentiary is a sure-fire way of sending shivers down your spine.

Just reading about its long haunted past is enough to get any Missourian nervous!