Keller House is a rare opportunity to occupy an entire historic mansion in the heart of Manhattan’s Upper East Side. Located just off Madison Avenue, the property spans approximately 25,000 square feet across multiple levels, combining the architectural presence of a Gilded Age residence with the flexibility required for contemporary brand experiences, exhibitions, private events, and executive gatherings.

Anchored by a dramatic double-height entrance lobby, a luminous glass conservatory, expansive entertaining spaces, and nearly 3,000 square feet of rooftop terraces, Keller House offers a highly adaptable setting for everything from intimate presentations to full-building takeovers. Available by individual floor, multiple-floor configuration, or exclusive buyout, the property is uniquely positioned for New York Fashion Week, Frieze, TEFAF, Design Week, luxury retail activations, private client events, and cultural programming.