<em>¿</em><em>Nosotros</em><em> estamos en Cancún?</em>
This translates as follows:
<em>Are </em><em>we</em><em> in Cancun?</em>
Nosotros is a subject pronoun for the first-person plural and means we. Recall that a subject pronoun replaces a noun in a sentence with the purpose of avoiding repetition.