This stone formation looks like two fried eggs, sunny side up. Apparently the center part was originally yellow, like the yoke of an egg, however thousands of people would rub them for good luck as they walked by and the yellow color wore off. I don't know how long ago that was, but I first went 30 years ago and they weren't yellow then either.
Date: June 15, 2013
Location: Luray Caverns, Luray, VA