Brierley's guidebook says that the difference in distance between the two routes to the castle is 0.9 km. However taking the southern route to Albergue Alea instead of the castle means you have to go further north and then head back to the east...
This site is run by Ivar at in Santiago de Compostela.
This site participates in the Amazon Affiliate program, designed to provide a means for Ivar to earn fees by linking to Amazon