Mont St. Michel used to be on an island that was only reachable when the tide was low. The tide careens in at 8 miles an hour, to over 50 feet, which was perilous for pilgrims wading towards the abbey. There is also an abundance of quicksand, another danger, and a thick, disorienting fog.
In 1878, the causeway I recently took was built to connect the Mont to the mainland, regardless of the tide, and to keep visitors out of harm’s way. Unfortunately, this causeway also stopped the flow of water around the island, which silted it up so it is no longer an island at all.
To counteract this, an ambitious project has been undertaken to create a footbridge between the mainland and the island, which will allow water to flow underneath it again. This project was started in 2010 and it scheduled to be completed in 2014.
There is only one main street (Rue Principale, also known as Grande Rue) on the Mont. Guidebooks will tell you to avoid it, and the accompanying tourist traffic, by walking up the ramparts. Personally, I thought it was charming and enjoyed our walk uphill.