Milecastle 38 is a milecastle fortlet (small fort) on Hadrian's Wall in the vicinity of Hotbank Farm. It is notable for the joint inscription bearing the names of the emperor Hadrian and Aulus Platorius Nepos, the governor of Brittania at the time the Wall was built.
The stone reads:
- IMP CAES TRAIAN
- HADRIANI AVG
- LEG II AVG
The first two lines identifies the emperor Hadrian, the third the Legion - Legio secunda Augusta (Second Augustan Legion) which erected the plaque, and the fourth the governor Aulus Platorius Nepos.