From Zaragoza to Sos, a 1 1/2-hour ride away, there is a daily bus at 7pm, returning at 7am the next morning.
To drive from Zaragoza, take the N-330 to Huesca. Continue on the N-330 to Jaca and then bear west on the N-240 toward Pamplona. Turn south at the cutoff to Sangüesa.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.