I've searched the internet for hostels in or around Aviles, Asturias but can't seem to find any. Any suggestions would be great.

There's one hostel in Avilés which I just now found by conducting a Google search using keywords AVILES +hostal

It's the Hostal Puente Azud @ http://www.usuarios.lycos.es/hostalpazudaviles/ (website only in Spanish). Prices seem pretty reasonable for a double. The building's recently been reformed/renovated and most all rooms have private bathrooms.

Good luck! And if you do decide to stay here, please do give us your review in this/your thread. Thanks!

Saludos, MadridMan

Thanks a million, looks great.