If you’re in or close to Mexico City be sure to check out Chapultepec Castle. The oldest part of the Castle was built in 1758 and used as a fort. In 1841 it was converted into a military academy. It was the site of a final battle against invading American troops. twenty years later it was remodeled into the residence of President Porfirio Diaz & was the official residence of the presidents of Mexico until 1944. It now houses the National Museum of History, a great place to visit to see remnants from Mexicos past. Amongst the many things there you can see the elegant coaches of King Maximilian, and get a look at some of the castles room to see how Royalty lived.
When Napoleon 3rd withdrew his supporting troops, Max & his wife were given the choice to leave with them but Carlotta liked being a Queen & didnt like the idea of having her status lowered to Duchess so she convinved Maximillian to stay, this eventually cost him his life in front of a firing squad in Queretero.
Chapultepec is the only castle on this side of the world to have had a monarch living in it.