Answer:
I have pen pals in Madrid, Spain, Lima, Peru, Veracruz, and Mexico.
Explanation:
In this sentence in particular " and " is used to present the last thing you listed. Es lo mismo cuando estan escibiendo en espanol y dice " Yo tengo amigos en Madrid, Espana, Lima, Peru, Veracruz, y Mexico." Where in this case " y " showed the sentence coming to a end. Other then that your sentence is correct.
