The Wissahickon Hermit Cave, also known as the Cave of Kelpius, is a small, man-made cave located on a hillside in a wooded area of Wissahickon Valley Park. It was built and utilized by the followers of Johannes Kelpius, a hermit and religious mystic of the Rosicrucian order who immigrated to the area from Germany in 1694 to meditate and await the end of the world.