Casa Batllo (World Heritage Site) - One of 2 houses by Gaudí in Barcelona that can be toured. truly amazing and worth the visit. go in the mornings, before the site gets crowded with architecture students.
Paris is stunning! The wildly gorgeous interior of the Church of Saint Etienne du Mont in the Latin Quarter. The steps of this church are used in Woody Allen's movie "Midnight in Paris" - but the interior is definitely worth seeing!
Le Procope is Paris' oldest cafe, dating back to the Starting as a cafe where gentlemen would drink coffee, it became a popular meeting place for intellectuals--such as Voltaire, Benjamin Franklin, and Thomas Jefferson-- throughout the century.