Roman Paris

November 2: If you have a Museum Pass, you can get into the Paris Crypt or Archeological Museum for free. It's buried just across the square from Notre Dame. Otherwise,it's not worth admission unless you're a history buff.

You'll find the crumbling foundations of old houses, sewer systems and baths dating back to the 4th century A.D., with scale models showing what the city looked like when the tourists hailed from Rome and spoke Latin. Many of the descriptions exist in English, though the explanatory video is only in French.