Set on nearly one private acre in the most coveted enclave of Mount Tiburon, 81 Mount Tiburon represents a rare opportunity to acquire one of Marin County's future landmark estates before completion. Positioned among some of the most significant luxury homes in the region, the property commands sweeping, unobstructed views spanning the San Francisco skyline, Bay Bridge, Golden Gate Bridge, Angel Island, Belvedere Island, and Mount Tamalpais. Currently undergoing a comprehensive transformation, the existing 3,599-square-foot residence is being reimagined into an approximately 4,500-square-foot contemporary estate designed to fully embrace its extraordinary setting. Architectural plans, engineering, and permitting are already in motion, allowing a future owner to step into a thoughtfully conceived vision with substantial groundwork underway. The proposed design centers around a dramatic great room with soaring ceilings, expansive walls of glass, and seamless indoor-outdoor flow. A chef's kitchen with an oversized island anchors the main living spaces, while panoramic views become the backdrop to everyday living and large-scale entertaining alike. The envisioned floor plan includes five bedrooms and four-and-a-half bathrooms, highlighted by a luxurious primary suite overlooking the Golden Gate Bridge, a main-level junior primary suite, and private guest accommodations designed for flexibility and comfort. Outside, the estate has been thoughtfully planned as a private resort environment. Expansive terraces, level lawns, a pool, wellness amenities, and multiple entertaining spaces create an atmosphere rarely found this close to San Francisco. A long private driveway, exceptional privacy, and an oversized two-car garage complete the offering. With irreplaceable views, nearly one acre of land, and a location surrounded by some of Marin County's highest-value sales, 81 Mount Tiburon offers a rare chance to secure a legacy property during its transformation. Targeted completion is April 2027. *Some images are digitally altered. Renderings and select images are architectural visualizations intended to illustrate the proposed design. Plans, specifications, and development details are available upon request.