Those strange looking stones are the remains of glider traps. Although most traps were removed about 60 years ago, there are still some broken remains on local beaches. Wooden posts were encased in concrete bases and then sunk into the sand with miles of barbed wire placed along the beaches in order to prevent enemy gliders or landing craft invading the east coast of Scotland during WW2. These are near Port Seton with several others further along the beach.
(The recent holiday photos have now been added starting here and I will shortly try to comment on blips)