Welcome to 21 Old Mill Street - A Grand Estate on 16 Private Acres with Over 8,100 Sq Ft of Living Space! Experience the perfect blend of luxury, functionality, and endless opportunity in this impressive 6-bedroom residence. Nestled on a quiet street with easy access to Hwy 403, this custom-built home offers over 8,100 sq ft of finished living space and is ideally suited for multi-generational living or the business owner seeking yard space and a home office. The home features a terrific in-law setup with a separate entrance, providing privacy and flexibility for extended family or business use. Inside, you're greeted by a grand foyer and an expansive open-concept main floor with 9 ceilings, granite countertops, and 250+ pot lights throughout for a bright, upscale ambiance. The sumptuous primary suite and three additional bedrooms on the main level provide space and comfort, while the fully finished lower level offers a home theatre, rec room, gym space, and more. A four-car detached garage, both drilled and dug wells, and an oversized septic system round out this one-of-a-kind estate. With 16 acres of land, the possibilities for outdoor enjoyment, hobby use, or future development are limitless.