Ohio can be pretty mysterious.

From sphere-shaped concrete houses in the middle of nowhere to subway systems that have never been used, the Buckeye State isn't always what it seems. The following are 11 mysterious, unusual spots in Ohio you might not have known exist.

1. Moonville (McArthur)

The abandoned coal mining town of Moonville in southeastern Ohio (Vinton County) was founded in 1856, when the Marietta and Cincinnati railroad ran through the area's woods. One structure of the town that remains today is the Moonville Tunnel; a haunted tunnel where legend has it the ghost of a man who was killed instantly by a train passing through the tunnel wanders along the track bed near the old tunnel at night.

2. The Round House (Logan)

Hidden along Old US 33 in Logan, Ohio stands this mysterious, round and concrete house. Weird Ohio reports that the house was built in the early 70s and completed in 1973 by a Mr. Stewart. Known as "Stewart's Folly," the round house was supposedly a prototype for a new, highly durable type of home for people that lived on hurricane-prone coasts. For unknown reasons, Stewart stopped production and never moved into the house as planned. Additionally, the blueprints and design notes were reportedly lost in a fire. Today, the strange house eerily sits abandoned in the Hocking Hills area.

3. The Wall of Gum (Grrenville)

Customers routinely discard chewed gum and stick it on the side of this Maid-Rite Drive-In in Greenville. Why? We're really not sure...

4. Findlay Ghost Town

Driving down St. Rt. 68, you might stumble across a sign that points the way to "Ghost Town." Created by the Galitza family, this unique roadside attraction in Findlay features a replica of an 1880s-era ghost town that was first open to the public in the 1950s. Today, the ghost town has an even more authentic ghost town feel due to a lack of upkeep and public attention.

5. The Mushroom House (Cincinnati)

This whimsical home is located in the Hyde Park section of CInnicati, and was designed by architect Terry Brown, a professor of Architecture and Interior Design at the University of Cincinnati.

6. Chippewa Lake Park

Tucked away in Medina County there’s a rusted, long forgotten ferris wheel. What what was once Chippewa Lake Park is now just a few piles of amusement park ruins and the lone ferris wheel. From 1878 to 1978, the amusement park was a popular, thriving destination for family entrainment. Today, remnants of it creepily stand abandoned, rusted and long forgotten. (If you think this abandoned amusement park would have been the perfect location for a horror film, you’re exactly right. In 2008, a cast and crew from Los Angeles filmed "Closed for the Season" here.)

7. Healing Chapel (Coolville)

Visit Ohio's (and one of America's) smallest chapels in Coolville. This tiny chapel is 10 ft. by 14 ft. and holds four short pews.

8. Futuro House (Carlisle)

Also known as the UFO house, this home in Carlisle was created by Matti Suuronen in 1968.

9. Cincinnati's abandoned subway

Not many people are aware of the dark, lonely and long-forgotten subway beneath the streets of Cincinnati—the country’s longest abandoned subway system that never transported a single individual. Located under Central Parkway in downtown Cincinnati, (from Walnut Street to just south of Hopple Street,) sits the incomplete, eerie series of tunnels, which have been abandoned since 1928.

10. Temple of Tolerance (Wapakoneta)

Jim Bowsher's home in the small town of Wapakoneta features an impressive museum of artifacts from the America you don't typically read about in history books, and a truly tranquil temple complex in his backyard. The central monument of the temple complex is dedicated to tolerance, and Bowsher continues to add to his unique creation to this day.

11. Blue Hole (Castalia)

This 1920s popular tourist attraction did not in fact die with the 90s. Castalia State Fish Hatchery holds another blue hole that's open to public observation and speculation about where this deep, blue water actually comes from.

What other mysterious and unusual spots are there in Ohio?