by Whatever
One of them, Le Louvre and its pyramids...Le Louvre has been opened since 1793. Within a decade, it had gathered the largest art collection, from Oriental to Egyptian antiquities, from Greek to Roman antiquities (Mona Lisa, Venus de Milo...), French, Dutch and Flemish paintings (Supper at Emmaus, Raft of Medusa....), and many more (about 300,000 artworks altogether!!!).
The Museum estimates that an average of 2 1/2 months would be needed to see every piece of art it contains! With a good pair of rollerblades, I bet it could all be done within a month! :)
LOCALS'SECRET: after a few days in Paris, you will soon grow tired of waiting in lines, so here is one of the secret entrances to the Louvre; rather than entering from the main Pyramide like everyone else, enter the museum from the subterranean concourse which can be accessed from the subway station's exit below. All you'll need to do is follow the signs pointing towards the Louvre's shops! There are a couple more secret entrances, but I was sworn to secrecy at birth...