Welcome to 517 N. Castellina Terrace, this EAST-FACING beauty is perfectly situated in the heart of Questa Village. Built by Shea Homes, the highly sought-after Umbria Plan 1 is arguably one of the most desirable single-story floorplans in all of Mountain House. This stunning home features 3 bedrooms, 2.5 bathrooms, and 2,488 sq ft of thoughtfully designed living space, all set on a impressive 11,517 sqft premium lot with no rear neighbors, backing to Great Valley Parkway. With over $270,000 in seller upgrades, this home effortlessly blends functionality with elevated design. Upon arrival, you're welcomed by a private open-air courtyard that connects to a third-car garageoffering potential for a 4th bedroom or flexible living space, originally an option by the builder. Inside, the home showcases a beautiful kitchen with dual islands and a wraparound seating area, perfect for gathering with family and friends. Additional highlights include a walk-in pantry, GE stainless steel appliances, a brand-new dishwasher and cooktop, and a tasteful backsplash. Recent upgrades include new carpet, fresh interior paint, and all-new LED lighting throughout. A fully paid-off 17-panel solar system adds both efficiency and long-term value. The primary suite offers a spa-like retreat, featuring an open-concept shower and soaking tub designed for relaxation. Step outside to a meticulously designed backyard that truly impresses, complete with a California room and fireplace, a modern lap pool with a hot tub and retractable cover, low-maintenance artificial turf, and exceptional privacy, perfect for entertaining or enjoying warm summer days. This home offers a seamless blend of comfort, style, and elegance. It has been exceptionally well cared for and is now ready for its next chapter.