Have you heard the story of the Horn Work in Marion Square? You know—that mysterious, unobtrusive, lumpy slab of concrete covered with oyster shells standing in the park near King Street? Did you know it’s actually a tiny remnant of a massive fortress that once controlled access to colonial-era Charleston? And it was the city’s first citadel during the American Revolution? The Horn Work is one of Charleston’s biggest secrets hiding in plain sight, and today we’ll review the most salient chapters of its must-read story.