Q: Given a travel related situation, and given a specific question about the situation, summarize the question into a title
I'm an American citizen traveling with Air France from Athens to JFK in New York via Paris. Do I need a transit visa to leave the airport and spend the night in Paris? Can I check a bag through or must I retrieve my luggage and go through immigration and customs?

Thank you.

A:
20-hour layover in Paris CDG, 5:15 pm to 1:50 pm