a nearly 400-foot-long linear structure off the coast of France [...] it measures roughly 66 feet wide at the base and stands roughly 7 feet tall
Sounds more like a jetty or causeway than a wall.

Notice Board
This is a work in progress, please don't mind the mess.
About
Archaeology or archeology[a] is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscapes.
Archaeology has various goals, which range from understanding culture history to reconstructing past lifeways to documenting and explaining changes in human societies through time.
The discipline involves surveying, excavation, and eventually analysis of data collected, to learn more about the past. In broad scope, archaeology relies on cross-disciplinary research. Read more...
Rules

Links
Archaeology 101:
Get Involved:
University and Field Work:
Jobs and Career:
Professional Organisations:
FOSS Tools:
Datasets:
Fun:
Other Resources:

Find us on Reddit

a nearly 400-foot-long linear structure off the coast of France [...] it measures roughly 66 feet wide at the base and stands roughly 7 feet tall
Sounds more like a jetty or causeway than a wall.
I donβt think they airplanes that long ago.
La Jette?
Iβm a bit disappointed all we have is one bad picture.
The article has linked to the paper, which has 21 photos and a bunch of maps and diagrams.
Awesome! I missed that, thank you :)
maginot line prototype