540 Sombrero Beach Road Located in Marathon's desirable Sombrero area, this waterfront home combines immediate boating access, thoughtfully designed outdoor living, and close proximity to Sombrero Beach. The property offers 76 feet of waterfront, a 40-foot dock, and immediate access to open water--an ideal setup for fishing, diving, or simply enjoying life on the water. When you're not on the boat, Sombrero Beach is just moments away. Recent improvements totaling more than $300, 000 have transformed the outdoor spaces into an extension of the home. A custom pool and spa with sun shelf, travertine decking, outdoor grilling and bar area, updated landscaping, extensive landscape lighting, multiple covered and screened patios, and a metal roof installed in 2021 are among the property's notable upgrades. A climate-controlled 500-square-foot lower-level bonus area provides additional flexible space for storage, recreation, hobbies, or a home gym. The property has also proven itself as a highly successful vacation rental, with 2026 year-to-date income and existing future bookings already exceeding $100, 000 net to the owner. The assumable flood insurance policy, currently just $1, 289 per year, further enhances the property's appeal. Looking ahead, existing architectural plans provide the opportunity to add three additional bedrooms, creating a five-bedroom home and further maximizing this sought-after Sombrero Beach location. Enjoy the home as it is today, with its proven rental performance, while retaining the option to expand in the future. Immediate boating access, proximity to Sombrero Beach, thoughtfully designed outdoor living, proven rental performance, and future expansion potential come together in a property that offers the best of Keys living.