Diver Finds Structure on Ocean Floor — Then Finds Out Why It’s There

It’s foundation

Eventually, the passage opened into the largest room yet. The ceiling arched impossibly high, supported by massive stone pillars. And that’s when he saw it: the unmistakable contour of the building’s main foundation. But there was a problem. Eli expected to see concrete flooring here. But there was nothing as if whatever this building rested upon years ago had vanished completely.