Maciek Nabrdalik Tourists on Mont-Saint-Michel look out over low tide. Maciek Nabrdalik Tourists mill about like subway commuters in the village, which has a full-time population of roughly 50.

At low tide, the sand flats surrounding the island, known as Baie du Mont St Michel, are revealed. This bay has the greatest tidal range in continental Europe, and witnessing the dramatic shift ...