The LAAA Team of Marcus and Millichap is pleased to present 4503 Castle Lane, a well-located triplex investment opportunity in the highly affluent and supply-constrained community of La Canada Flintridge. Built in 1952, the property offers investors a rare opportunity to acquire a boutique, low-density residential asset in one of the most desirable foothill submarkets in Los Angeles County, known for its strong demographics, top-tier schools, and long-term appreciation fundamentals. The property consists of one (1) one-bedroom/one-bathroom unit measuring approximately 635 square feet and two (2) two-bedroom/one-bathroom units measuring approximately 850 square feet each, providing an attractive balance of affordability and livability for a broad tenant base. The two bedroom units are well-suited for small families or roommates, supporting strong tenant retention and income stability. Select units have been upgraded with new wood flooring, fresh interior paint, updated lighting, and modern finishes. A standout one-bedroom unit features double French doors opening to a spacious private patio and large fenced yard, a rare amenity for multifamily properties in this submarket. Additional interior features include kitchens with granite countertops and maple cabinetry, in-unit washer and dryer connections, porcelain appointed bathrooms, central heating, wall air conditioning, ceiling fans, and ample storage. The property offers covered tuck-under carport parking, additional storage, and a large common deck area. The existing tuck-under parking configuration presents a compelling value-add opportunity to construct an approximately 400-square-foot studio ADU, subject to buyer verification. Under California's current ADU legislation and the City of La Canada Flintridge's local ordinance, this addition could meaningfully increase both unit count and income in a high-barrier-to-entry submarket where new supply is extremely limited. 4503 Castle Lane is ideally situated near the heart of the Montrose district, moments from the Montrose Shopping Park, a vibrant pedestrian oriented retail corridor with boutique shops, restaurants, cafes, and a popular weekly farmers market. The property benefits from direct freeway access via the 210 and 2 Freeways, connecting residents to Pasadena, Glendale, Burbank, and Downtown Los Angeles. The Jet Propulsion Laboratory (JPL) is within 3 miles, anchoring a highly educated, high-income renter demographic that sustains consistently low vacancy in this submarket.