The McDonald’s restaurant in Downey, California, is the oldest surviving location and preserves the chain’s early Golden Arches design.
The Downey restaurant opened in 1953, making it one of the earliest restaurants operated under the McDonald brothers’ developing brand. Its building retains the original 1950s architectural style, including the prominent roadside arches that helped make McDonald’s visually distinctive.
The location was opened by Roger Williams and Burdette Landon, who became McDonald’s franchisees. It was not the first McDonald’s restaurant ever opened, because the original San Bernardino site predates it. However, the San Bernardino building was later replaced, while the Downey site survived.
The Des Plaines, Illinois, location is another important historical site: it was Ray Kroc’s first McDonald’s restaurant and is reconstructed as a museum. That makes Des Plaines a common answer to a different question, not to the oldest surviving-location question.