Unlike most bridges that are meant to stretch over bodies of water, the Nebraska Bridge near Tionesta, Pennsylvania, is actually expected to be underwater for at least a few weeks every year. Even on a “good” day, the bridge sits just inches above the water level. Due to constantly changing water levels, the bridge goes from almost completely underwater to being fully functional.

What geniuses would build such a thing? Well, the bridge wasn’t always like this. It was erected in 1933, designed to cross the Tionesta Creek in northwestern Pennsylvania and serve the small lumber town of Nebraska.

But as activity and development grew along the nearby Allegheny River, the United States Army Corps of Engineers built the Tionesta Dam to protect communities downstream from flooding. The dam was put into service in 1940, which meant the community of Nebraska would literally be underwater. Residents packed up, but the bridge stayed in place, and for decades, it has disappeared and reappeared again and again as water levels rise and fall behind the dam.

The bridge has become a regional legend. It even has its own Facebook page and will be featured in a 2019 documentary film. It stands almost like a ghost of days gone by.

And, as it turns out, the people who built the bridge back in 1933 did a good job after all. The bridge has been flooding over for the better part of a century, and—when not submerged—it continues to be fully intact, functional, and travelable.