EXTREMELY RARE- Custom High End Build! Enjoy the best of both worlds, situated on the border where Newport Beach meets Huntington Beach in the coveted Luxury Coastal Community of Orange County. A stone’s throw to the sand and sea of iconic Surf City, there has never been a Single-Story Estate of this size and stature to hit the market in this area. Boasting an expansive Quarter of an Acre Lot. 9601 Castine Drive is nestled into the private end of a Cul-de-Sac with nearly 5,000 sq. ft. of living space that makes this unique Modern Industrial Home a true masterpiece. Enter through the custom glass double doors into a spacious Open Floor Plan with Vaulted Ceilings and multiple living spaces, living room, dining area, family room with built in bar, opens onto the pristine Entertainer's Backyard with Sparkling Saltwater Pool and Spa. All 4 bedrooms and bathrooms are located on the main floor, with an additional upstairs Loft/Bonus Room. The oversized Master Retreat features fireplace, walk in closet, and soaking tub. The back yard has a detached structure currently used as a gym, but great potential use as Casita/Mother In Law Suite. This home also includes a private attached Spa Room and Security and Outdoor Lighting System. Rest your cars and toys in the Custom 3 Car Garage with vaulted ceilings, commercial epoxy flooring, and recessed motorcycle alcove. This home goes well beneath the surface level with meticulous attention to detail and added upgrades. MUST SEE!