LOS ANGELES (AP) — Days after the discover and swift disappearance of two shining metal monoliths spotted half a world away from each other, another towering structure has popped up, this time in Southern California. Its straight sides and height appear similar to one discovered in the Utah desert and another that was found in Romania. Like those structures, the origins of the California edifice are also mysterious. KEYT-TV reports that it’s at the top of a hill in Atascadero, about halfway between San Francisco and Los Angeles. The tall, silver structure drew hikers to the area after photos were posted on social media.