h.p Lovecraft 
The Transition of Juan Romero [EPUB ebook] 

The story involves a mine that uncovers a very deep chasm, too deep for any sounding lines to hit bottom. The night after the discovery of the abyss the narrator and one of the mine’s workers, a Mexican called Juan Romero, venture inside the mine, drawn against their will by a mysterious rhythmical throbbing in the ground.