Penthouse 15B is a rare and architecturally distinctive duplex offering approximately 1,735 square feet of elegant interior living space and two private terraces high above Carnegie Hill. Quiet and sun-filled, this exceptional residence combines soaring volume, a wood-burning fireplace, expansive outdoor space, and panoramic city and East River views, an extraordinary combination seldom found in the neighborhood. The first level is designed for gracious entertaining. A dramatic living room with a vaulted ceiling is anchored by a striking double-sided wood-burning fireplace, creating warmth and architectural presence. Floor-to-ceiling glass doors open to a wraparound terrace spanning the length of the home, offering breathtaking open views and a seamless extension of the living space, ideal for dining, relaxing, and entertaining. The open gourmet kitchen is both refined and functional, featuring a Wolf range and microwave, Sub-Zero refrigerator, wine cooler, ice maker, and an expansive marble-topped island that serves as a breakfast bar and natural gathering place. An elegant dining area flows effortlessly into the kitchen and living space, creating an ideal layout for both everyday living and hosting. This level also includes a versatile third bedroom or home office, with a full bathroom, privately positioned. A striking floating glass staircase leads to the upper level. The tranquil, south-facing primary suite is flooded with natural light and features an en-suite marble bath with heated floors and a steam shower, along with three closets, including a custom walk-in. The second bedroom offers its own en-suite bath and direct access to a generous north-facing terrace with a retractable awning, an intimate and private outdoor retreat. The residence is enhanced by Savant and Lutron smart home technology controlling lighting and custom shades, Sonos audio throughout, through-wall heating and air conditioning with individual room controls, and an in-home washer and dryer. The Royal Carnegie is a full-service, pet-friendly boutique condominium with a full-time doorman and staff, fitness center, and beautifully maintained garden. Perfectly positioned on a tree-lined Carnegie Hill street moments from Central Park, Museum Mile, Madison Avenue shopping, fine dining, top hospitals, schools, and buses and subway, Penthouse 15B offers a rare opportunity to own a true penthouse with exceptional light, outdoor space, and architectural character in one of Manhattan's most coveted neighborhoods.