Quite a similar sort of road to the Cat and Fiddle really, (i.e. very good but also very busy) The notorioty of the area means that you need to be on high alert for police pretty much continuously.
This road winds through a spectacular gorge, some fast sweepy sections and a great set of hairpins. watch out for the 'tunnel du tende, a long, dark, narrow and bumpy tunnel with artics coming down the middle of the road at you. Apart from that, a blinder of a road and a great way to get to the Med, or even better, turn off at Breil and take the D2204 to Sospel and Nice.
Route 103 in Northern Portugal runs from Braga in the West to Braganca in the East. About 200 kilometres of absolutely stunning mountain road. Traffic is generally light and the road surface, by and large, is excellent. Chaves, about half way, makes a nice stop off point and the opportunity to refuel self and bike. The western section is largely fast, open sweepers, the eastern has a lot more tight and twisty stuff. Ride it, you'll love it!
A really good selection of tight hairpins, fast sweepers and a nice view as the road rises up from sea level to around 1000m. As this is rural Spain, you may need to pay some attention to farm animals straying into the road (although I didn't see any on the way). This route is ideal if you've just got off the ferry from Santander.
Quite a similar sort of road to the Cat and Fiddle really, (i.e. very good but also very busy) The notorioty of the area means that you need to be on high alert for police pretty much continuously.