Two Royal Naval 6" Gun Platforms that protected Lowestoft Harbour that fell on to the beach in 1940 at Pakefield and then get covered by sand until the next rough weather exposes them again
FXT
Dunwich
Felixstowe Beach Suffolk by John Cooper, on Flickr
https://heritage.suffolk.gov.uk/media/pdfs/ww2_guidebook1_lowestoft_to_southwoldweb.pdf