On this map, made by Blondel from sources by LeVau when he imagined what is nox the Institute, the traces of the Nesles Tower
We have outlined in red the old layout of the river Seine banks, in green the tower of Nesles and its staircase, in blue the nesles gate and the general orientation of the wall .
The one under is the same place and was taken by Arthur Gilette in the early 90s.
Cliqck on the image to enlarge (176k, 1536x846 px)
see rue du louvre