The old town is the main event in Aínsa. The Plaza Mayor, the Castillo de Aínsa, and the Iglesia de Santa María are all within a few minutes' walk of each other. Beyond the old town, Ordesa y Monte Perdido National Park is the main draw — the Añisclo and Pineta sectors are both accessible from Aínsa, offering canyon hiking without the summer crowds of the main Ordesa valley.