My pick
My tip“Photography is prohibited inside; book a specific time online. The temperature is 12°, so bring a jacket.”
Discovered by zinc and lead miners in the 20th century, and world-famous for its density of “asymmetric stalactites” (the eccentrics), which grow in every direction, defying gravity. You enter by the old mine train.
Easy to reach, needs a car
A winding mountain road (20 min) from Cabezón/Celis to a car park beside the entrance. The standard tour is on prepared walkways, ~1 hour, temperature 11° inside. Restaurant on site. Fog is common on the road.
Address
Prao el Colla s/n, Celis