Welcome to 25 South Mill Street - a rare offering of newer construction (built in 2013) located on the waterfront in one of Portsmouth's most sought-after neighborhoods. This thoughtfully designed two-family home presents a unique opportunity to own a versatile, income-generating property in a premier location. Each of the two units features 2 bedrooms, 1 full bath, and in-unit laundry, offering comfortable, modern living with a coastal flair. The upper unit enjoys elevated views and higher ceilings, maximizing light and enhancing the stunning water vistas. Outdoors, you'll find no shortage of parking with a deep, oversized garage (approx. 14' x 26') and a driveway that accommodates 6+ vehicles - an exceptional amenity for South End living. With flexible use options, this property is ideal for an owner-occupant looking to offset their costs with rental income, investors seeking a premium location asset, or those envisioning a condo conversion or conversion to a single-family residence. The upper unit is currently vacant in order to make showing the property easier (most recently rented in 2025 for $2900/month), while the lower unit is leased through April 2026, providing both immediate flexibility and reliable income. Don't miss this exceptional opportunity in the heart of the South End - just a short stroll to downtown Portsmouth, Prescott Park, and the city's vibrant waterfront scene.