The Antram-Gray House, which serves as the visitor center for Roger Williams National Memorial, is located at the northeast corner of the park at the corner of North Main and Smith Streets. It is an early 18th century structure with a late 18th century addition. The original, north portion of the house was built c. 1730 on the west, or water, side of North Main Street, a very early road originally called Towne Street. This portion of the house is one of the few structures in Providence that survive from the city's earliest period of commercial and maritime development.

Over its almost 280 year history, the structure has seen many uses: private residence, grocery and dry goods shop, dressmaker's shop, liquor store, hairdresser, restaurant, barber, and watch shop. When the National Park Service took ownership of the building in 1974, it was moved approximately 40 feet to the south of its original location to enable Smith Street to be widened.  Today, the Antram-Gray House holds interpretive exhibits and staff offices.