Blue Ash is certainly known for many remarkable things — a large 150-foot observation tower at Summit Park, the second location of Over-the-Rhine’s Senate, etc. — and one of those happens to be a purported tunnel to the netherworld. The story goes, local Satanic groups would meet at a drainage tunnel in Blue Ash to conduct rituals and, in doing so, opened a portal to hell itself. The graffiti tagged abyss has pentagrams and phrases like “Hell lies ahead” sprayed on the walls and lots of stagnant, standing water. Many have also reported screams, trapped spirits and apparitions including “The Shadow Man” — some sort of demon. Wanna check it out for yourself? Alas, Satan’s Hollow is on private property. Instead, you might have to settle for checking out Satan’s Hollow: The Tunnel to Hell, a short, 10-minute paranormal investigation “documentary” about the spot released in 2012. It’s on YouTube.