The top of the wall enclosing the courtyard is just a few inches higher than the stone wall going down to the water. There is a narrow stairway (descending to the Memorial courtyard) near where several people can be seen, and another like it on the other side. The top of the second one can just be seen, appearing from this perspective immediately to the right of the tree at the near left.
This is the very tip, somewhat narrow, of the island that holds Notre Dame, Ile de la Cité. In the distance is Ile St. Louis.