A hidden oasis where the trails begin! Tucked into a lush, private half-acre in Lorton's Mason Neck, this custom home is a rare find in Fairfax County. A true zen oasis with meandering paths through meticulous landscaping and mountain bike and hiking trails at your back door. Mason Neck State Park, Pohick Bay Regional Park, and Gunston Hall just minutes away. Inside, Pride of ownership is evident throughout this thoughtfully designed home. Offering five bedrooms plus a dedicated office, including a private upper-level suite complete with its own entrance, kitchenette, and sun deck, the flexible floor plan is ideal for multigenerational living, guests, remote work, or extended stays. The exterior is equally impressive with Hardie Plank and stone siding, a detached workshop garage, brand-new asphalt driveway, and beautifully landscaped grounds designed to blend seamlessly with the surrounding natural environment. The detached garage offers outstanding workshop space and is roughed in for future plumbing, creating endless possibilities for hobbyists, mechanics, or future expansion. Brand-new asphalt driveway. No HOA. Extensively upgraded for comfort, efficiency, and future readiness, the home features a newly completed 400-amp electrical heavy-up that distinguishes this home from ordinary. The upgraded service provides exceptional capacity for today's technology-rich, energy-intensive households and is fully configured for the addition of multiple EV charging stations. The geothermal system at the heart of this home is a custom, two-zone installation — one of the most efficient and durable climate solutions available for a residential property. An electric heat pack provides backup heating capacity, ensuring performance even in the coldest weather. The system is divided into independently controlled zones for personalized comfort throughout the home, and delivers consistent year-round temperature management at dramatically reduced utility costs compared to conventional HVAC. A whole-house steam humidifier maintains healthy indoor air quality, and a high-MERV advanced air filtration system keeps airborne allergens and particulates in check. Two premium Stiebel Eltron tankless water heaters — positioned at the bathrooms they serve — deliver instant hot water on demand with minimal waste. An additional 80-gallon water heater provides whole-house capacity for high-demand situations. This thoughtfully designed home boasts efficiency, comfort, and functionality in alluring Mason Neck. Perfect for multigenerational living, home-based businesses, hobbyists, outdoor enthusiasts, and anyone seeking a private retreat without sacrificing convenience. It’s not just a home, it’s a lifestyle.