O'Cebreiro, Parking and return transport

Parking at O Cebreiro is a real challenge. It's a very popular tourist site year-round, and the Guardia enthusiastically employ tow-trucks to enforce the tough parking regulations.
You'll do best to park in Pedrafita do Cebreiro, the larger town 3 km. down the mountain. They have a huge wintertime paved lot just off the autopista for when the mountain pass closes. I wouldn't call it "secure parking," but it's what there is. You can come back on the bus, Santiago-Lugo-Pedrafita.

ALSA provides service from Santiago bus station to Piedrafita do Cebreiro. (note the spelling)

Alternatively;

Empresa Freire provides bus service from Santiago bus station to Lugo;

and , Gonzalez de la Riva provides bus service from Lugo to Pedrafita do Cebreiro. See Concello de Pedrafita (not to be confused with Concello de Pedrafita do Cebreiro) for Gonzalez Schedule

Empresa Monforte (Monbus) provides bus service from Pedrafita do Cebreiro to O Cebreiro once daily. You'd be better off taking a taxi or walking.