Milecastle 9 (Chapel House) was a milecastle of the Roman Hadrian's Wall. Its remains exist partially as a low platform, and are located in West Denton (to the west of Newcastle upon Tyne), 300 yards (270 m) from Chapel House Farm. However, the northern part of the remains are now mostly covered by the modern roads (A69/B6528). The milecastle marks a watershed between those with relatively well defined positions (to the west) and those whose position are less certain (to the east).