Good news: Las Medulas is a stop on the Camino Invierno, a waymarked alternative camino that departs from the
Camino Frances in Ponferrada. It´s a very cool place, but if you intend to return to the Frances to continue your camino, you´d be well-advised to take a cab or bus to visit the site, as it´s 30 km. of walking from Ponferrada.
Alternatively, if you´d like to see the charming mountain pilgrimage site at Peñalba, you can take a bus there from Ponferrada during tourist season, or hike up there following a map available at the tourist office near the castle.
If you´re adventurous and have time and energy, you can take in BOTH Peñalba and Las Medulas, following El Circular del Bierzo, a trail blazed by local hiking fans. It leaves the Frances in El Acebo, passes through Compludo (a Roman-Mozarabic town) and over a couple of mountains, all of it in solitary glory. Peñalba is not the friendliest place, it´s been restored to within an inch of its life for tourist trade, but it´s very much worth a visit -- especially the cave of San Genadio! The following day (the toughest day I ever spent on a camino) you follow 30 kms of mountain trail/Roman canal works past a spectacular mountaintop labyrinth and on to a 1,500-year-old monastic mountain ruin, and from there logging roads on to Las Medulas. It is waymarked, sparsely but adequately, and it puts you neatly onto the Camino Invierno.
It´s all do-able. Problem is, trail information is so hard to locate out there -- they spend all the effort and money to create a trail, but leave nothing in the budget for promoting it!
