| Milecastle 39 | |
|---|---|
 The remains of Milecastle 39, near Steel Rigg | |
  Location within Northumberland | |
| Type | Milecastle |
| Place in the Roman world | |
| Province | Britannia |
| Structure | |
| — Stone structure — | |
| Size and area | 19 m × 15.5 m (0.03 ha) |
| Location | |
| Coordinates | 55°00′13″N 2°22′33″W / 55.003602°N 2.375725°W |
| County | Northumberland |
| Country | England |
| Reference | |
| UK-OSNG reference | NY76066773 |
Milecastle 39 (Castle Nick) is a milecastle on Hadrian's Wall (grid reference NY76066773).