John In 1988 the Mont-Saint-Michel was used as a (very) short-lived gnomon. It was designed and set up to work only a few days around fall equinox. So it had only the equinox line marked with huge digits. And it was flood twice a day by the tide ! The spire of the church at the summit was 150 m high.
You can find a photo at the following site : http://maget.maget.free.fr/SiteMont/Fotoindex1.html with many other interesting informations Best regards Jean-Paul Cornec Lannion France
