A World War 2 partially buried brick and concrete square structure at the top of Burgh Island, Bigbury-on-Sea, Devon, England.
This was probably an observation post and is adjacent to the Huer's Hut (https://skfb.ly/ooZsB). It is not clear how the buildings would have been related or used together during the War.
https://archaeologydataservice.ac.uk/archives/view/dob/ai_full_r.cfm?refno=6604
753 photos taken in August 2021 with a Sony a6000 and processed in Reality Capture.