Cite de l'Architecture et du Patrimone is what I think might just be Paris' best kept secret. Rarely do I find anyone who has visited, but I was awestruck the first time I stepped inside. It's the world's largest architecture museum. Located at Trocadero Palace et de Chaillot, overlooking la Tour, it is not to be missed. Oh and have your coffee on the terrace. You get the same commanding view of la Tour for a fraction of the price. You'll thank me for that!