Two Mid-Century Modern Homes on One Lot near Downtown Boulder. Rarely does a property like this come to market in one of Boulder's most sought-after neighborhoods. Located near 4th & Marine, this legal non-conforming duplex features two separate mid-century modern homes on one lot, each with 2 bedrooms, 1 bathroom, built-in storage, and walls of natural light. The front house was built in 1946 and the back house was constructed in 1960. A shared courtyard connects the homes providing both covered and open patio space with opportunities for gardening, entertaining, or future additions. Inside, each home was designed with comfortable living in mind, offering smart layouts, storage solutions, and timeless mid-century character. Additional features include a shared laundry room and easy access to Boulder's best amenities. Just blocks from Downtown Boulder, Boulder Creek, and Eben G. Fine Park, the location combines convenience with a peaceful residential feel. With multiple paths forward-income property, multi-generational living, owner-occupant with rental, or full renovation and expansion-this property offers unparalleled flexibility and long-term potential in a prime Boulder location.