Caves have long afforded protection to humans - even in recent years. During the Civil War, residents of Sharpsburg were scrambling for refuge from Antietam, the bloodiest battle of the Civil War. Luckily, Killiansburg Cave was nearby. With its mossy overhang and towering trees surrounding it, you would never guess that frightened, dirty, and hungry civilians cowered here in terror. While Killiansburg Cave sustained them temporarily, they returned to ruined homesteads.