Rarely does a property emerge that perfectly captures the essence of Eastside Costa Mesa luxury while offering the rare scale of an 8,712 sq. ft. parcel. 308 E 18th Street is a contemporary showpiece defined by its substantial estate footprint, standing out as a premier find in this coveted coastal enclave. The grounds' versatility creates a serene sense of privacy and provides a limitless canvas for a sophisticated outdoor lifestyle. Imagine this space as the ultimate stage for premier entertaining: a custom outdoor pavilion for year-round lounging, a sun-drenched alfresco dining area for long summer evenings, and the glow of string lights creating a magical ambiance for hosting under the stars. Whether you dream of a professionally landscaped garden retreat or a high-end social hub, this expansive land offers a level of creative freedom that is rare in the area. This sense of refinement continues indoors, where the home has been thoughtfully reimagined to balance modern architecture with bespoke comfort. The heart of the residence is an open-concept chef's kitchen, fully equipped with professional-grade Thermador appliances and a generous social island designed for grand-scale hosting. New, upgraded flooring flows seamlessly into the light-filled living area, anchored by a stunning, redesigned focal-point fireplace. The transition to the second level leads to a primary suite that serves as a true sanctuary. This private retreat features a balcony, a newly added linear fireplace for a sleek modern touch, and a resort-like bath complete with a soaking tub and steam shower for a daily spa experience. Step outside to discover a private oasis defined by a quiet backdrop and significant usable open space, a retreat that serves as the perfect foundation for your outdoor vision. Beyond the property lines, the location offers the quintessential Eastside lifestyle, situated within the prestigious Newport-Mesa Unified School District (Mariners Elementary/Newport Harbor High). Living here means you are just minutes from the trendiest dining and boutiques on 17th Street, the scenic trails of the Newport Back Bay, and world-famous beaches. This is a rare opportunity to secure a turn-key designer home on a substantial, one-of-a-kind lot in one of Orange County's most coveted neighborhoods.