(Kaytlyn Leslie | The Tribune (of San Luis Obispo) via AP) A monolith stands on a Stadium Park hillside in Atascadero, Calif., Tuesday, Dec. 2, 2020. Days after the discovery and swift disappearance of two shining metal monoliths half a world apart, another towering structure has popped up, this time at the pinnacle of a trail in Southern California. Its straight sides and height are similar to one discovered in the Utah desert and another found in Romania. A group of men tore the structure down Thursday.