A high-quality Peninsula duplex with stable income, minimal expense drag, and clearly defined long-term upside.117 N. Delaware Street presents a rare opportunity to acquire a well-located duplex in the heart of San Mateo. The property consists of two large units, each configured as 3 bedrooms and 2 bathrooms with garage parking offering strong fundamentals for both owner-occupiers and long-term investors. With tenants in place for over 20 years, the asset provides stable in-place income and a clear path for predictable rent growth under California rent control guidelines. The property currently generates $7,610 per month ($91,320 annually), with a highly efficient expense. Market rents for comparable units are estimated at approximately $4,500+ per month, indicating meaningful long-term upside. At market levels, the property would generate approximately $108,000. Generous layouts, strong rental demand and a desirable unit mix support long-term growth and income optimization. Don't miss this rare opportunity whether as an investment or a property you could occupy!