Set on one of Park Slope s most coveted, tree-lined blocks, this extraordinary historic brownstone at 509 3rd Street embodies the timeless elegance and architectural grandeur that define Brownstone Brooklyn. Built in 1899, this distinguished two-family residence currently configured as an expansive single-family home seamlessly blends original period craftsmanship with the warmth and scale of classic townhouse living. Located in the heart of Center Slope, the property offers a premier location squarely positioned within the highly coveted P.S. 321 elementary school attendance zone. Ascend the stately stone stoop and enter into a world of timeless Brooklyn elegance, where the home's stunning allure and classic woodwork details immediately captivate. The grand entryway unfolds into an impressive parlor sequence defined by soaring ceilings, graceful proportions, and an abundance of natural light pouring through oversized windows. Rich original crown moldings frame each space with sophistication, while exquisite cherry and oak millwork showcases the unparalleled artistry of a bygone era. Gleaming original hardwood floors run continuously throughout, anchoring the home with warmth, character, and an unmistakable sense of historical authenticity. Designed for both grand-scale entertaining and comfortable daily living, the residence features a highly practical layout where each of the upper bedrooms is beautifully and nicely sized, offering rare comfort, excellent closet potential, and grand proportions. Every floor presents a versatile canvas, whether envisioned as a trophy single-family masterpiece, an owner s triplex paired with an income-producing rental, or a multi-generational residence. For those looking to maximize the property's footprint, the estate includes approximately 1,489 square feet of unused FAR, offering lucrative potential for a seamless vertical or rear expansion. The broader stretch of 3rd Street where the house sits is itself historically notable. Historians and architectural writers frequently describe the blocks between 7th Avenue and Prospect Park West as among Park Slope s grandest residential streets because of their unusual width, mature trees, and intact late-Victorian row houses. Architecturally, 509 3rd Street is tied to a larger 1892 93 development associated with the nearby apartment building known as The Annandale Apartments at 203 7th Avenue, designed by architect Lewis Anderson. Preservation historians note that while the development originally included four brownstones on 3rd Street, 509 3rd Street is the only one of those original houses included within the Park Slope Historic District today. This makes the building a proud, singular part of the Romanesque Revival wave that transformed Park Slope after the opening of Prospect Park. A true testament to its meticulous stewardship, the lucky next owner of this property will be only the fourth owner to live here in over a century. Outside your door, original brownstone charm pairs effortlessly with the enduring appeal of Park Slope s landmarked streetscape. Residents will enjoy immediate access to the neighborhood's finest boutique shopping, cafes, and culinary institutions, including Vato, Il Leone, Sotto Voce, Bar Louise, Pino's Famous Pizzeria, Sushi Katsuei, and Variety Coffee Rosters. You are positioned just two blocks from the rolling lawns of Prospect Park and moments away from JJ Byrne Park and its vibrant weekend farmers market. Ideally situated for an effortless commute, the home is exceptionally close to the F train at 7th Ave, the Q and B at Flatbush, the 2/3 at Grand Army Plaza, and the N/R at 9th Street and Union Street stations. Don't miss this rare opportunity to acquire a pristine piece of historic New York City real estate on a benchmark Park Slope block. Call, email, or text to schedule your private showing.