| Lock Name: | Carthagena Lock |
| Waterway: | River Lee Navigation |
| County: | Hertfordshire Essex |
| Operation: | Manual |
| Maint: | Canal & River Trust |
| Length: | 85feet |
| Width: | 16feet |
| Fall: | 5feet |
| Enda: | Bow Creek |
| Distenda: | 17.5miles |
| Endb: | Hertford Castle Weir |
| Distendb: | 8.8miles |
| Coordinates: | 51.7436°N -0.0021°W |
Carthagena Lock (No7) is a lock on the River Lee Navigation at Broxbourne
Directly behind the lock is Carthagena Weir part of a fishery which also includes two lakes and a section of the Old River Lea.
To the east of the lock is the Nazeing Mead complex of lakes which incorporate part of the River Lee Flood Relief Channel.
Vehicular access via B194 Nazeing New Road
Pedestrian and cycle access via the towpath which forms part of the Lea Valley Walk
There is a water point for boats. The tap is in the lock.