My family will be in Zaragoza this winter and we would like to go to Castillo de Loarre. My guide books do have some information - it looks like we can take a train to Ayerbe and then a taxi to the castle. Can anyone confirm that we can in fact take a taxi from Ayerbe, and whether this will be possible in January?

Thank you!

Ummm, I don't know about taking taxis in Ayerbe. It doesn't sound right...
All the times I went to the castle it was by car and it seems that's the way most people do it unless you take an organized excursion and then they'll take you by bus.
The bus company Alosa serves most of the Pirineos and they have a couple buses a day from Huesca to Ayerbe. The buses stop at Loarre but I'm guessing is the town, not the castle. Here is the website -in Spanish I'm afraid- http://www.alosa.es/
Or maybe you can contact somebody at the castle directly, this is their website http://www.castillodeloarre.com/
Good luck and enjoy the castle, it's beautiful!! But bundle up you'll be cold in December.
Chus