The Tidal Gates. Designed to allow the tide rise and the sea to enter the pool.
They were closed, and the sluices closed, until the right time, and the sluices opened.
The area is fenced off, not supposed to be down there, but hey, what are they going to do?
Looking at the gate edges, it appears that they were edged with bands of oiled leather.
9th May 2009.