This wonderful single-level Mid-Century home located in the Huntington Library district of San Marino, offers an exceptional opportunity to create a very special custom residence. One block from Lacy Park and situated on a large lot with a 458 sq ft guest house, 1591 Charlton Rd is central to Valentine and Huntington Middle School, the Crowell Public Library, and the Huntington Library, Art Museum, and Botanical Gardens. Built in 1952, this 4 bed/3 bath home's public spaces orient towards the picturesque gardens and sparkling pool, showcasing a wall of windows and sliding glass doors leading to the rear patio and pool area. The spacious living room features a stone fireplace and opens to a formal dining room and sunporch. The kitchen has granite counters, a breakfast nook, and a separate laundry/mudroom with sink and abundant cabinet space. The library/den is located off the kitchen and features a fireplace and built-in bookshelves. There are 4 bedrooms; a master suite with newer bath and separate vanity, a large tub & shower and two spacious bedrooms that share a hall bath. The 4th bedroom with a 3/4 hall bath is located off the kitchen/laundry area. Perfect for entertaining, the expansive rear yard showcases a lovely backyard filled with beautiful plantings, including loquat and lemon trees. There is a large rectangular pool, two changing rooms with a sitting area, a 2-car garage connected by a covered breezeway, and a guest house with kitchenette and 3/4 bath. Exquisite architectural details throughout and located in the award winning San Marino school district.