The Pyrenees are loads better, bigger roads and great twisty passes. I have loads of routes there as go on a regular basis. Did the Picos once and as some have said its limited and the roads are okay but not fantastic and would nor do them again as ticked that one off the Pyrenees keep calling me back. Like you Wales is also my back yard and ride at least 1000 miles a month in that area (weather and work permitting) .
In contrast, I did the Pyrenees last year, Picos earlier this month. I preferred the Picos myself. Thought the area was a great place. I download som GPX routes from ride magazine website.
Never been to the Picos, will get round to it one day Pyrenees last week - the Spanish side, Bardenas Reales area. Aguero area
Done both Picos and Pyrenees, Picos all day long for me, roads are far quieter, we stayed at Potes for the duration, so many roads to choose from. Will be going back next year hopefully, Ferry prices £550each with 4 sharing a cabin for July next year. 21 hours crossing from Plymouth normally go Sunday arrive Monday mid-afternoon back following Thursday for Plymouth Friday mid-morning, so 9 full days + the ferry arrive & depart days. Or you could 4 to 5 days at both Places
I really like the Picos area, you could also sneak in a bit of the northern Pyrenees on the same trip. I’ve got some gps routes of the roads we visited this year and also from the Multistrada meeting a few years ago. I’ll send you a pm to get an email.
Did the Picos in September. Less traffic, plan your routes with google streetview. Highly recommended.
