Set atop a classic Upper West Side brownstone, this four-bedroom, three-and-a-half-bath penthouse offers 2,677 square feet of comfortable sophistication along with 436 square feet of private outdoor space, including a sun-filled rooftop terrace. Thoughtfully updated, it blends the warmth of historic architecture with the ease of modern living. The main level is designed for gathering and everyday enjoyment. A generous kitchen centers the floor, featuring Calacatta Viola marble countertops, Molteni cabinetry, Waterworks fixtures, and a full suite of Gaggenau appliances. Its oversized island invites casual meals or conversation while cooking, and a terrace just beyond makes the perfect spot for morning coffee or evening drinks. Beyond a graceful archway, large living and dining rooms retain the scale and charm of classic brownstone interiors, enhanced by paneling, crown moldings, and soft natural light. A stylish powder room with a Jade Crystal stone vanity adds convenience for guests. Upstairs, the primary suite overlooks the garden and includes a serene bath with dual vanities in Arabescato Turquoise marble, a rain shower lined in Alaska White stone, a five-foot soaking tub, radiant-heated floors, and a private water closet. Two additional bedrooms enjoy southern sunlight and share a skylit bath, while a discreet laundry closet completes this level. A curved staircase leads to the penthouse studio, offering a full bath and access to a spacious roof terrace. Perfect for a home office, guest suite, or quiet retreat, it provides a peaceful escape high above the city. Combining generous living space, inviting outdoor areas, and timeless brownstone character, the residence at 344 West 84th Street is an exceptional opportunity in one of Manhattans most sought-after neighborhoods.