W. W. McCormick of Abilene, Texas, reported his grandfather's account of a stone block wall that was found deep within a coal mine: "In the year 1928, I, Atlas Almon Mathis, was working in coal mine No. 5., located two miles north of Heavener, Oklahoma. This was a shaft mine, and they told us it was two miles deep. The mine was so deep that they let us down into it on an elevator.... They pumped air down to us, it was so deep." One evening, Mathis was blasting coal loose by explosives in "room 24" of this mine. "The next morning," said Mathis, "there were several concrete blocks laying in the room. These blocks were 12-inch cubes and were so smooth and polished on the outside that all six sides could serve as mirrors. Yet they were full of gravel, because I chipped one of them open with my pick, and it was plain concrete inside." Mathis added: "As I started to timber the room up, it caved in; and I barely escaped. When I came back after the cave-in, a solid wall of these polished blocks was left exposed. About 100 to 150 yards farther down our air core, another miner struck this same wall, or one very similar." The coal in the mine was Carboniferous, which would mean the wall was at least 286 million years old. According to Mathis, the mining company officers immediately pulled the men out of the mine and forbade them to speak about what they had seen. Mathis said the Wilburton miners also told of finding "a solid block of silver in the shape of a barrel... with the prints of the staves on it," in an area of coal dating between 280 and 320 million years ago. What advance civilization built this wall?... Why was the truth, as is so many of these cases protected and hidden?... What is the real truth about time travlers, modern humans, and modern technology in our past?