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

Estimating the size

His eyes widened behind the mask. The chamber around him was enormous, easily the size of a football field, maybe larger. He hovered in the middle of it, stunned by the scale, by the sheer size of what had remained hidden beneath the ocean floor for who knows how long. Whatever this place was, it wasn’t meant to be found easily.