A curious siuation.I've not been able to show it here,but each of these pillboxes,and I saw four,had firing positions,either side of the sea dyke,they are apparently projecting from,yet no obvious door/entry point.That is weird,because,on all other pillboxes I've seen,the entry point is very obvious.This suggests to me that,either,the sea dyke was constructed after the war,or,there is a tunnel entry to the pillboxes.see http://en.wikipedia.org/wiki/British_hardened_field_defences_of_World_War_II