Halloween may be the day we dedicate to horror, but the spooks and spirits of Illinois are anything but seasonal. Illinois hosts hundreds of haunted historical sites. As scary as these destinations are, the terrifying tales that accompany them are really the stuff of nightmares. Here are four spine-tingling ghost stories still spooking the Prairie State today.

But be warned. Some of these tales take place in locations that you can still visit and make great destinations for scare-seekers. Others are abandoned, burned, forbidden, or a combination of the three. So, make sure to do your homework before setting off on a spirit quest, and don’t say we didn’t try to warn you.

1. Sugar Tree Grove Cemetery (Monmouth)

The history of the secluded Sugar Tree Grove Cemetery is a tale of violence, misplaced retribution, and guilt. During the 1830s, white settlers colonized the Monmouth area. On farmland stolen from the Indigenous Sauk people, they built a church and began to bury their dead. As the conflict between the colonists and the Sauk tribe escalated during The Black Hawk War, colonists grew increasingly reluctant to leave their secured camps after dark.

That is, colonists other than William Martin, who, allegedly under the influence of drink, wandered into a field one night where he was killed by five members of the Sauk tribe. The turn in this tale is that, in the European colonists' rash efforts to avenge Martin, they formed a mob and murdered an Indigenous person without any certainty that he was involved in Martin's death. In a strange display of guilt, the Sugar Tree Grove Cemetery bears a grave to the unjustly killed Sauk man. The tombstone's inscription refers to the "Indian" as a "Son of Abraham." But this gesture of remorse has seemingly proved inadequate. Now, it is rumored that one can hear distant drums and chanting voices at the cemetery. Visitors also report unexplained wind and cold and an unnatural dread the takes hold after dark. While it doesn't seem to have an exact address, which only adds to its mystery, Sugar Tree Grove Cemetery is located in Warren County near Monmouth, IL 61462.

2. Sylvan Island (Moline / Rock Island)

Sylvan Island has its own historical ties to the Black Hawk War. Used by the Indigenous Fox people for a variety of purposes, colonizers would seize control of the land and, after the Civil War, develop it into an industrial hub. Sylvan Island became an island because workers demolished the land that connected it to the shore to increase the output of the dams powering the island and neighboring Rock Island Arsenal.

According to lore, all types of spirits congregate on Sylvan Island. Over a dozen people have drowned, died in accidents, or otherwise left this world on Sylvan Island. Some say that Indigenous spirits on the island are responsible for playing drums to warn visitors of the presence of other, dark spirits. Sylvan Island has recently reopened to the public, so you can check it out yourself. Find Sylvan Island at 1st Ave & 2nd Street, Moline, IL 61265.

3. Lakeview/Hartford Castle (Hartford)

The story of Hartford Castle, originally called Lakeview, is both tragic and terrifying. Originally constructed by a French immigrant as a gift for his bride, the towering mansion would never meet its intended inhabitant. Before construction was complete, the French woman died, and her husband abandoned the property. Afterward, the mansion passed through a number of owners and even briefly operated as a speakeasy. No matter who owned the place, though, the reports of moving furniture, of death and bad luck befalling those who lived or stayed there, and of a ghostly apparition of a dead, French bride, remained the same.

After falling into disuse and disrepair, Hartford Castle burned in the 1970s. Today, only its stone remnants are left to decorate the woods. But ghosts, I'd imagine, aren't very picky about climate control. You can't legally visit this spot, located at IL-3, Hartford, IL 62048. You're probably safer that way.

4. The Devil's Bake Oven / The Devil's Backbone (Grand Tower)

In this picture, you see the grown-over ruins of the foundry house that once stood on Devil's Bake Oven. Devil's Bake Oven and its sister, The Devil's Backbone, are two geological formations on the bank of the Mississippi River in Grand Tower. Once the cause of frequent shipwrecks, the devil's rocks soon became well-known landmarks. But this didn't stop their association with death. When Illinois industrialized, Grand Tower became the site of a foundry. The superintendent of that foundry, the story goes, had a house built on The Devil's Bake Oven. The superintendent had a daughter. He was a possessive and cruel parent, but could not keep her from falling in love with a local man. He could, however, keep her from seeing him. He shut his daughter up in the foundry house. Her lover would not return, and, abandoned, she would weep until she died. Now, her spirit roams the area. Some have described it as a wandering mist, as if her ghost itself was made from the tears she spilled over the loss of her lover.

Before you leave for your next spooky adventure, be sure to visit Devil's Backbone Recreational area. It may not be haunted, or at least as haunted, but it is hauntingly beautiful. One of the closest spots to The Devil's Back Oven and Backbone that has a real address, Devil's Backbone Park is located at 1921 Brunkhorst Ave, Grand Tower, IL 62942.

The four brief, historical horrors recounted here only account for a sliver of the spirits haunting Illinois and barely scratch the surface of the state's ghostly lore and legends. Feel free to use them for your own ghost-storytelling purposes next time you're around the campfire or just looking to freak out a friend.

What are your favorite anecdotes about unnerving and unexplained events in Illinois? Is there one place we should check out for the chills (or avoid at all costs)? We love hearing your ghost stories and seeing your photos. Get in touch!