Architecturally relevant and thoughtfully reimagined, 105 Marsdale Drive is an inspiring mid-century modern "Butterfly Roof" bungalow, offering nearly 3,000 square feet of main-level living in one of South St. Catharine's' most highly sought-after neighbourhoods. Originally designed in 1958 by Massey Award-winning architect James E. Secord, with a later addition influenced by renowned architect Ron Thom, this home blends preserved architectural character with modern updates. Features include floor-to-ceiling glass, clean horizontal lines, custom rosewood built-ins, and four fireplaces (3 wood-burning, 1 gas). The open-concept layout flows seamlessly through the living, dining, and kitchen areas, creating an ideal space for both everyday living and entertaining. The private backyard oasis is a standout feature, professionally landscaped and designed for resort-style living. Highlights include a Swenker concrete pool, hot tub, outdoor barbecue kitchen, pool change room, low-voltage landscape lighting, and a programmable in-ground sprinkler system. The fully finished lower level offers a self-contained suite with a separate entrance, two bedrooms, a full kitchen, spacious living areas, and a full bathroom - ideal for multigenerational living, growing teenagers, guests, or a nanny/in-law setup. Additional features include an original indoor cedar-lined sauna with shower, extensive storage, cedar-lined closets, and mature award-winning landscaped gardens providing exceptional privacy. Located just steps from the Niagara Escarpment, Bruce Trail, Ridley College, the Pen Centre, and some of Niagara's top wineries and Michelin star restaurants. A rare opportunity to own an architecturally significant mid-century modern home with exceptional lifestyle flexibility in a prime location.