IIRC a friend of his was involved in setting it up. I've found a similar site, but it uses overlays where you can change the transparency. It's good for overlaying older maps to see the locations of features that have been demolished etc. might be of interest to UKCers:
The French equivalent of OS (IGN) have a site where you can look at a variety of maps & aerial photographs at scales from maybe 1:5 000 upwards. Its possible to alter the transparency with eg an aerial photo overlain by a semi-transparent map, see https://www.geoportail.gouv.fr/
The Irish Government today announced the creation of a new National Park, the country's eighth. Located on the Dingle Peninsula, Páírc Náisiúnta na Mara, Ciarraí includes the rugged Conor Pass, the unique island of Sceilg Mhichíl, and Mount Brandon, one of...