The Beach - London, South Bank

When the tide goes out there is a beach along most of the South Bank. It ranges from slippery rocks, near the low-tide line, to a fine sandy beach up near the edge of the river.  Looking down from a jetty by the Oxo tower you see many stone objects, thrown into the river from boats or from the river bank.  Bricks, chalk, flints, or concrete; none of these would be in this place naturally.
Together they form a pleasing pattern, in my eyes at least!
This picture was taken early in the day on a riverside walk. Later in the day we went to the Tate Britain to see the Turner and the William Blake collections. (See extra)