Northernhay Gardens are located in Exeter, Devon, England, on the northern side of Rougemont Castle. They are the oldest public open space in England, being originally laid out in 1612 as a pleasure walk for Exeter residents. The gardens are Grade II listed in the National Register of Historic Parks and Gardens,and are currently maintained by Exeter City Council. The site was originally quarried in Roman times for stone for the city walls. The gardens themselves incorporate a stretch of Roman wall and the only length of Saxon town wall to be seen in England.