Ideally situated on the flat of Charlestown, moments from Main Street, the Navy Yard, and the waterfront, 12 Auburn Street offers a rare blend of scale, flexibility, and historic character. Spanning four levels and over 3,350 square feet, this brick brownstone lives as a spacious single-family home while offering a separate garden-level residence with private front and rear access. Features include three bedrooms, three and one half renovated baths, four fireplaces, an updated kitchen, entertainment room, private deck, and patio. Complete with one deeded garage space and two transferable off-street spaces, this is a rare opportunity to own a home in Charlestown with unique versatility.