Residence 3C at 279 Sterling Place offers a truly distinctive opportunity to own a former classroom thoughtfully transformed into a sun-drenched duplex studio within one of Prospect Heights' most architecturally significant cooperative buildings. Originally constructed in 1895 as Public School 9 Annex and masterfully designed by renowned Brooklyn architect James W. Naughton in the Romanesque Revival style, this landmarked structure-listed on the National Register of Historic Places-was converted to a residential co-op in 1989, preserving its extraordinary scale, craftsmanship, and historic soul. Once a space of learning and imagination, Residence 3C now embodies the romance of adaptive reuse, where soaring ceilings and oversized windows-true to its original classroom proportions-flood the open living and dining area with natural light, creating a sense of volume and airiness rarely found in studio living. The thoughtfully designed duplex layout maximizes vertical space, with a lofted sleeping area perched above the main living level, offering both architectural interest and functional separation. Hardwood flooring runs throughout, grounding the dramatic ceiling heights with warmth and texture, while a separate kitchen provides practical delineation without compromising the loft-like flow. A full bath completes the home, and the overall configuration delivers flexibility, efficiency, and character in equal measure. P.S. 9 Annex itself is a meticulously maintained elevator cooperative featuring a beautifully landscaped common courtyard, a striking facade of brick, sandstone, and terra cotta with neo-classical detailing, and an undeniable presence at the corner of Sterling Place and Vanderbilt Avenue. Positioned just moments from Grand Army Plaza, Prospect Park, the Brooklyn Botanic Garden, the Brooklyn Museum, and the Brooklyn Public Library, and surrounded by the vibrant dining and boutique corridors of Vanderbilt, Washington, and Flatbush Avenues, this location places you at the cultural and recreational heart of Brooklyn, with seamless access to the 2, 3, B, and Q subway lines. Pets are permitted upon approval. Residence 3C is more than a studio-it is the opportunity to live within a piece of Brooklyn history, where grand architecture, natural light, and neighborhood vitality converge to create a home that feels both inspiring and deeply rooted in place. Photos are virtually staged.