Put aside its collections, Louvre Museum's exhibition has the worst design among those Europeans museums and galleries we have visited.
After entering the Pyramid of the Museum, there are two separate entrances to the exhibition halls. One long long queue is only marked "Mona Lisa" (and no more details).
We arrive in early morning and therefore queue up for "Mona Lisa" first to avoid the crowds. We waited in the queue for about half hour to see the painting, and then follow the "exit" sign leaving the section shortly afterwards.
We then go through other exhibitions, but find that the paintings in the whole Level 2 of Richelieu Wing (actually where Mona Lisa is located) can't be reached. We asked the staff (totally five 5 persons) before we are told that we have to queue up again the Mona Lisa line in order to see other paintings at Level 2 of Richelieu Wing!
Firstly, if the museum think that visitors are all coming only for Mona Lisa, then they should separate this painting from all other exhibitions (like Lady with an Ermine in Krakow). Otherwise, they should write down on the sign "Level 2 Richelieu Wing (include Mona Lisa)" at the long queue. This would remind visitors they are queuing up not only for Mona Lisa, but also other French and European paintings located there!
Besides, visitors are not allowed to go from one wing to another (Richelieu and Sully Wings) in each floor (forbidden by staff there) except Level -1. This is not shown up clearly in the floor plan leaflet provided by the Museum (only distingished by different colours). Therefore visitors need to pass through the exhibitions halls repeatedly to find their way to another side of the same floor.