The portal to this sinisterly named tunnel is in the most unlikely location: behind a Tim Hortons in Ohio’s capital. The inside of the passage is covered in graffiti, which quickly disappears within the darkness.

The Gates of Hell (also called the Portal to Hell and the Blood Bowl) is a drainage tunnel under North High Street. Entering the tunnel, which requires you to step into the mouth of a graffiti monster, leads to a dank stretch of utter blackness.

The tunnel earned what may be its most disturbing nickname, the Blood Bowl, because of an urban legend about a skateboarder who died there in the 1980s. But it’s also possible that it may have gained this reputation partly because of the many skateboarders who’ve wiped out while trying to conquer its steep walls in the dark.

Though urban explorers do wander into the tunnel, it’s technically off limits to the public. It was built for a stream that goes from Glen Echo Park to the Olentangy River, but is mostly dry, except after rain. A cage-like structure near the entrance of the tunnel prevents large debris from being lodged inside.