Camino the other way around, from Santiago to Porto?

Yes, but only as far as the old border at Tui/Valenca do Minho. December 2011 after finishing the CF I continued to Finisterre, per usual, and then walked down to the Portuguese border at Tui. This involved going " backward " along the Camino Portugues from Santiago. To go backward is more complicated than you might think; since the path was hardly well marked, searching for the famous yellow arrows pointing opposite my direction wasn't easy. Viewed backwards the arrows resembled anchors. Thus it all was a bit of a treasure hunt! No problem staying in the Xunta de Galicia albergues which were GREAT and well heated. Since it was close to Christmas often I was the only pilgrim.

Bom Caminho,

Margaret Meredith

Has Margaret said, it can be tricky.

BUT, be aware that there is an effort to mark a way, with blue arrows from Santiago untill Fatima, and that way, always have to pass in Porto. I remember seeing some blue arrows on the Caminho, pointing on the opposite direction, but probably it's not the same way, has the one that goes from Porto to Santiago (they don't pass on the same places, it's what I’m trying to say).

There are other people here in the Forum who have done it, or are intending to do it, you just have to search it, I've met a couple last year who went from Santiago to Lisbon, after doing the Frances, and this year, other couple doing Santiago to Fatima.

So, who knows how many people you are going to find on the same situation