Remnants

Ghostly remnants, perhaps.  These are the defences on the beach at Kimmeridge Bay, the pillbox full of large pebbles, the blocks improbably arranged in the centre of a small valley leading from the beach.   They are remnants of a time when there was a risk of invasion from the south, but presumably no one could work out how to move them; or perhaps they were left as a memorial of some sort.