Set on one of the Upper East Side’s most beautiful blocks, just off Museum Mile, this full-floor penthouse tucked inside a 1920s Neoclassical brownstone is a design lover’s dream. Two bedrooms. Two baths. North and south exposures. Three oversized arched windows draw soft northern light into the living room, framing the pre-war architecture across the street and giving the home a real sense of place. Ten-foot ceilings and original oak floors add volume and warmth, while a working wood-burning fireplace anchors the room. The kitchen is recently updated, with generous storage, a new Fisher & Paykel refrigerator, and Bosch dishwasher. In the bathrooms, classic white tile and warm wood sit alongside clean, modern fixtures. At the rear of the apartment, the primary bedroom looks onto a quiet garden, with a decorative fireplace, two closets, and large windows. The second bedroom, currently a home office, faces an ivy-covered wall: a particularly peaceful place to work, or to retreat. The building itself has the intimacy of a private home. Originally built as a single-family residence and converted to a co-op around 1980. There are just four shareholders across five floors. This beautifully maintained co-op permits pied-à-terres, has a washer/dryer in the basement, and does not allow pets.