Ready to build! Nestled in the heart of San Marino’s most prestigious and established estate enclave, Oak Knoll Avenue presents a rare and extraordinary opportunity to secure one of the finest legacy residential parcels in the area. Located just moments from the iconic Langham Hotel and a short stroll to the beloved Lacy Park, this nearly 31,000-square-foot flat lot offers unmatched privacy, scale, and development potential in one of Southern California’s most highly regarded neighborhoods. The property is offered primarily for land value, providing an exceptional canvas for the creation of a world-class custom residence. The existing home is planned to be removed, and the sale includes fully developed and submitted architectural plans for an elegant 5,935-square-foot two-story Spanish-inspired luxury estate with a three-car garage. This design concept embraces timeless architectural character, refined indoor-outdoor living, and modern lifestyle functionality—perfectly aligned with the area’s historic charm and luxury standards. With a wide frontage, generous setbacks, mature trees, and expansive grounds, the site affords both privacy and presence, offering the flexibility to create a resort-like environment with pool, gardens, and multiple outdoor entertainment zones. The parcel’s impressive lot size also presents potential for additional improvements, including an ADU or guest casita, subject to city approval—further enhancing the long-term value and versatility of the site. Located within the boundaries of the award-winning San Marino School District and surrounded by many of the city’s most iconic estates, this address is synonymous with enduring prestige, architectural excellence, and generational value. Opportunities to acquire large, build-ready estate parcels in this prime heritage zone are exceedingly limited, particularly those accompanied by pre-planned luxury home designs that honor the neighborhood’s character while meeting modern standards of scale, livability, and privacy. A rare blend of location, scale, architectural vision, and development readiness, this estate-caliber parcel invites its next steward to bring a dream home to life in one of the most distinguished pockets of San Marino.