The Ordesa shuttle is not glamorous, but it is one of the most important practical details in Torla. During the busiest periods, buses carry visitors from the car park below town into the Ordesa valley, keeping private traffic out of the narrow park road.
Buy tickets early in peak season and do not assume you can improvise at noon. If you want the classic hike to Cola de Caballo, catching an early bus makes the whole day better.