#10 is indeed Mexico City.  It would be another consular tour for me, interviewing 100+ people a day, but the food would be fantastic!

Here’s #11.

The country is a constitutional monarchy and shares the longest undefended international border.  The population density of the country is among the lowest in the world.  This city is built on an island which has a three-headed hill on it.  Some believe this is how it received its name.  Of course, it also used to be called Ville-Marie (City of Mary).  It is one of the five largest French-speaking cities in the world.  During winter months, it can be colder than Moscow or Saint Petersburg.