Well if it's mines you want ...
From the Picos "ring road" at the large reservoir at Riano take the A-625 then turn along the AS-117, signposted Oviedo. This is a great riding road with excellent views and mountains all around (lots of twisties). the road surface starts off a bit rubbish but slowly improves. After you pass the Embalse de Tanes you will enter the village of Rioseco where we stayed at a great hotel. The Don Feliz is like a Brit. boutique hotel without the price tag. They let me park the bike in their garden area just outside the front door. Highly recommended. There are at least two good restaurants in the town too.
Now the tour ...
Stay on this road as it gets more and more industrialised, you'll pass a few mines until you get to El Entrego which has one of the best mining museums I've been in (I've been in a few).
http://www.mumi.es/
Give yourself 3 hours for a proper look around.
From there I rode directly over the tops on the LA-7. This road has lots of mines all around, each one in really beautiful surroundings, most of them sadly closed, some only recently as the Spanish economy has gone tits up and the mining subsidy has been removed. You'll see lots of people wearing black ribbons and black ribbon symbols daubed on walls. Last summer we even managed unwittingly to get involved in a protest which turned a bit nasty - time for a sharp exit! One of the mines on the LA-7 has been turned into an Ecocentre (it closed as a mine in 2002) but I didn't stop - I'd be interested to know what's there.
You get so used to seeing British mines (well you did before the 1980's) in a kind of industrial wasteland that headframes in these beautiful wooded mountains are a bit of a shock.
We explored a few mining sites on foot, but be careful shafts are unfenced!!!! Locals are very friendly especially if you can profess solidarity with the cause. Industrial relations are very 1970's with the hammer and sickle painted on walls etc.
The LA-7 took us over the top to the AS-337 - fab road with lots of exciting detours and a nice restaurant/bar with good views where the two meet. The AS337 (back towards the Oviedo/Leon Road) along the valley of the Turon is an industrial archaeology paradise. There are mining remains every few Km.
For example ...
Campo del Tabla is a mine with an horrific story to tell - just read the interpretation boards and weep! You'll need a bit of Spanish but you'll get the gist with a phrase book.
At Santandres there's a headframe that looks like a swiss chalet on stilts!
San Francisco has an old steam loco near the roundabout and a very modern (and closed) mine. You have to go round the one way system to see it. Lots of great revolutionary murals around.
When I hit the A-66 I went (towards Leon) up to Pola de Lena and then took the AS-231. The road has more mines and precipitous drops. Just follow it until it reaches the N-630 and back to the A-66. AS-116 back towards Langreo and the mining museum or stay on the A-66 and go towards Oviedo, Gijon and the coast.
You can check out the route on Google Maps. You'll see that the views are spectacular to say the least.
https://maps.google.co.uk/maps?f=d&...0.126286,0.308647&vpsrc=6&hl=en&mra=ls&num=10