Newly completed, The Onyx stands as one of the most significant residential offerings ever brought to market in Westlake Hills. Defined by rare elevation, sweeping downtown views, and a level of execution that is exceptionally difficult to achieve, this architectural estate delivers scale, presence, and privacy at a standard few homes ever reach.Arrival unfolds through a secure, gated, and privately walled approach—substantial, architectural, and deliberately set apart.Spanning approximately 11,000 square feet on nearly an acre, The Onyx was built by Paradisa Homes with an uncompromising focus on proportion, durability, and enduring quality. Walls of glass shape the living environment throughout the home, including a custom Fleetwood Edge sliding system—one of only two installations of this caliber and scale in the United States, and the largest of its kind—opening the residence to uninterrupted downtown and Hill Country views that extend far beyond the glass.Interior volumes are striking, with ceiling heights reaching up to 18 feet, creating moments that feel expansive, architectural, and powerful without excess. Light moves through the home deliberately, shifting throughout the day and framing the city in a way that continually reinforces the home’s elevation and vantage point.The kitchen is anchored by a 12-foot Milano marble island that reads as sculpture as much as surface. Gaggenau appliances, custom cabinetry, and refined material selections support serious cooking and effortless entertaining alike, while a fully equipped catering kitchen with Thermador appliances allows hosting to unfold seamlessly behind the scenes. For the wine collector, a glass-enclosed wine vault with capacity for approximately 600 bottles becomes part of the architecture itself.An entire level of the home is dedicated to the owner’s suite—an intentional design choice that creates true separation and privacy. This floor includes a private lounge, a striking office, two walk-in closets, a safe room, and commanding downtown views that feel immersive rather than distant. The bathroom is extraordinary: a sculptural stone soaking tub, oversized rain shower, and floor-to-ceiling glass framing the city beyond. It is, without exaggeration, one of the most remarkable primary baths ever executed in this market.Designed to adapt effortlessly to the moment, the home offers a private theater suitable for intimate performances and events, a fitness studio with steam shower, a refined library, and an entertainment level with full bar that opens directly to the pool. Ascending by elevator to the fourth floor reveals the Sky Parlor—a rooftop indoor-outdoor entertaining level where the skyline feels close enough to touch and the city becomes part of the setting.The exterior is equally considered in both scale and intention. A resort-style pool and spa are complemented by a cabana with swim-up bar, outdoor kitchen, pool bath, and expansive lawns with space suitable for a pickleball court.A detached guest house provides true privacy and independence, complete with its own kitchen, living space, and en-suite bedroom—ideal for long-term guests or extended stays.For collectors, the garage accommodates 6 to 12 vehicles with lift capability, blending presentation and function without compromise.For those seeking additional scale, an adjacent property may be available, offering the opportunity to expand the total estate to approximately 1.72 acres, enhancing privacy and long-term flexibility.Located within Eanes ISD—one of the most highly regarded school districts in Texas—and just minutes from downtown Austin, private aviation, and the city’s most desirable dining and cultural destinations, The Onyx occupies a position that is both commanding and exceptionally rare.