This is known as the La Cruz de Ferro. There is a lot of stuff on the internet about this so I won't go into much detail. You are supposed to add a stone or token of love and blessing to the pile. I must say that the walk from there down to Molinaseca was very difficult for me. The path had lots of rocks and boulders and was very steep in places. Next year I plan to take the road (dangerous as it is) from just before getting to Acebo and take my chances.
@Dennis D Hola Dennis - I rode my cycle down from the Cross to Acebo and Molinaseca and I would actually advise against following the road after Manjarin and also after Acebo - its very steep (in sections) AND there are cars/trucks using the road as well. So I suggest following the trail and take it slow and steady. Cheers.
@Saint Mike II - Hello Mike. Thanks for your advice. My comments were made after I walked my first Camino. Last year I took the road from Collada de las Antenas to About 2 km before Acebo and the trail all the way to the bottom of the hill just out of Molinaseca. That worked fine for me.
What happened to me on the first year was I managed to get dehydrated. That, plus the steep trail, sort of kicked my butt.
This year I plan to spend the night in Acebo, so it should be much more fun getting down that hill.