This is one of the best sites in France. Accessible at all times but more specatcular on the high tides it is a great place to visit.
The Abbey itelf is open only at daytimes but MSM itself is open all day and night. There are hotels and eateries located on MSM that are open into the night.
One of the two big questions are 1. How do I get there and 2. How long do I need to see it?
1. Go to the Forum section and decide if the train, bus, or car good for you. It is possible to day trip from Paris.
2. If you have enough time then stay then night near MSM but I would suggest not to stay on MSM. The hotels are expensive and the eateries not the best. There are many places around the abbey.
Parking is about 2 Kms away with a shuttle available to take you to the base of MSM
Once at MSM you will pass through many souvenir stores that are greatly overpriced. Making your way up to the top to the Abbey will include a gradual incline and steps. If you are in average health this will not be a problem but on summer days you will need to stop in one of the many air con shops along the way. Once at the top you'll pay an entrance fee into the Abbey. There are tours at specific times of the day listed on the Abbey's website.
The Abbey itself should take no more than one hour to see. Load up some chamber or chanting monk music on your Iphone to enhance the atmposphere and drown out the tourists. There is an Abbey gift store at the exit/entrance point of the Abbey.
At lower tides there is a tour you can take around the exterior of MSM. It is well worth the fun but bring a change of clothes. Night time photos are great around the Abbey at night but entrance into the Abbey is not allowed at night.
There are places to eat, museums, and stores on MSM.
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