Welcome to 433 3rd Street, Unit 3 - a spacious and light-filled four-bedroom, one-and-a-half-bath home located on one of Park Slope's most beloved tree-lined blocks. Just one flight up in a charming self-managed eight-unit cooperative, this residence offers generous proportions, classic architectural detail, and a warm, inviting layout. The home opens to a gracious floor plan with soaring ceilings, original hardwood floors, and beautiful historic moldings throughout. The expansive living room features a lovely bay window with custom shades and built-in bookshelves spanning an entire wall, creating a perfect space for relaxing or entertaining. A generous formal dining room easily accommodates a large table for gatherings and dinner parties. A large south-facing bedroom with double windows sits between the living and dining rooms, filling the space with natural light. These main rooms enjoy bright southern and western exposures, creating a sunny and welcoming atmosphere throughout the day. The windowed eat-in kitchen is generously sized and easily fits a table and chairs. It features Carrara marble countertops and includes a full-sized, vented washer and dryer - an uncommon luxury in pre-war apartments. Three additional bedrooms are located across a long, gracious hallway. These tranquil north-facing rooms each include a closet, and overlook neighboring gardens. The apartment also includes a windowed full bathroom with a soaking tub, along with a more recently added and very convenient half bath. Residents of this well-maintained cooperative enjoy beautifully landscaped common front gardens; a peaceful spot for morning coffee or an evening glass of wine. Additional amenities include deeded generous basement storage, bike storage, and covered stroller parking. The building is a financially sound, self-managed co-op with low maintenance. Cats are welcome, though dogs are not permitted. Ideally located in the heart of Prime Park Slope, the home is just moments from Prospect Park, JJ Byrne Playground, the Greenmarket, the library, and the many cafés, restaurants, and shops that define the neighborhood. Nearby transportation includes the B, Q, F, and R trains. Currently zoned for PS 321. With its spacious layout, abundant light, and timeless architectural details, Unit 3 offers a wonderful opportunity to enjoy classic Brooklyn living on one of Park Slope's most cherished blocks.