On this episode of Under Rocks , we don't turn over any stones, but we take you face-to-face with a massive chunk of concrete along an Ogle County roadside. Like many northern Illinois residents, Dan Libman was worried that when a certain DeKalb bookstore closed, he might never again be able to use the word “Grotto.” But that was before he made a discovery on a bike ride. On an ordinary corner in Stillman Valley stands something quite extraordinary: A concrete shrine, complete with arches and a