Santiago Cathedral - Early Chapel

That's an intriguing question! By 'early chapel behind the main cathedral' I would assume they mean the Capilla de la Corticela, which is on the NE side (assuming 'behind' means 'east end'), and was a separate building until the 17th century, used by foreign pilgrims. However, AFAICS, the photo you provide is not of this chapel, and I don't recall it being 'covered with scallop shells' anyway; nor can I see any shells on the photo. If you go to http://maps.peterrobins.co.uk/files/birdseye.html and swivel round, you can see if you can spot where this photo was taken, but nothing immediately springs to mind.

Any large-scale shell decoration is almost certainly baroque/post-medieval, but I can't offhand recall anything like that in Santiago.

yup, that's the one. A bogus caption in the article, and nothing to do with Santiago! It seems there is a depiction inside this chapel of the Virgin del Mar with large scallop shell, so presumably that is the other scallop-shell association, with Venus (as in 'vieira', which comes from 'venera').

And apparently Franco liked to spend his holidays in Toja - one learns something new every day . . .

Re: Santiago Cathedral - Early Chapel - La Toja

Is this the one? My pilgrim friend in Galacia lives nearby and sent the pictures.
Outside wall covered with the flat bottoms of coquilles Saint Jacques (vieiras).

PS: There is more (names) than meets the eye:

More on the Ermita de San Sebastián on http://www.trivago.es/la-toja-102646/ca ... /fotos/x10

Original hermitage in the Toja
In the island of the Toja, in the municipality of Or Grove, is forced visit this most original hermitage, whose origin is placed in century XII, although the present plant is of the XIX. It is not that architectonic it has special interest, nor their interior is especially rich or valuable, but is a very singular construction, because she covered with scallop shells is all, absolutely everything!

http://www.infohub.com/TRAVEL/SIT/sit_pages/11232.html

The maritime and river route along the Arousa estuary and the river Ulla commemorates, according to tradition, the arrival by sea to Galicia of the body of the Apostle St. James the Greater, after his martyrdom in Jerusalem in the year 44 AD. St. James was a sailor and fisherman from Galilee, an apostle of Christ, the evangelizer of the West, and a martyr. The episode on his death, ordered by Herod Agrippa, is contained in St. Luke's "Acts of the Apostles". We disembark in O Grove and board our Mini-van to take us to a luxurious Spa hotel on La Toja Island. Here we stop to see an interesting Church decorated with Scallop shell (A cultural symbol of the Camino) on the exterior.

http://www.onpedia.com/destinations/eur ... oxa-island
La Toja/A Toxa Island, together with the Island of Arousa, one of the great island spaces in the province. Joined to O Grove peninsula through a bridge built at the beginning of the present century, A Toxa started to develop as a result of the construction of its spa. Hotels and sports and leisure centres sprouted up round it. Its natural locations and the peculiar hermitage of San Caralampio (12th cent.), covered with scallop shells, are of particular beauty.

Also see Georgiana's Gems #9 Iria Flavia (Padr6n) by PILGRIMSPLAZA on April 15th, 2009, 2:19 am on santiago-to-finisterre-and-muxia/topic5804.html#p33917

Foto ermita toja http://videospark.webcindario.com/o%20grove.htm

Traslación del Apóstol Santiago. Año 1610

the arrival by sea to Galicia of the body of the Apostle St. James the Greater

Click to expand...

This picture I just found in Cancionero de los peregrinos de Santiago by Pedro Echevarria Bravo; published by the Centro de Estudios Jacobeos, Madrid 1971 that I purchased at ₧ 750 on November 2nd 1988 on our second visit to Santiago that year in Libreria González in the Rúa del Villar.
Actually I had asked for The Cantigas de Santa Maria ( http://www.pbm.com/~lindahl/cantigas with a link to the most exquisite medieval illuminations) but the staff couldn't find it. Already back in the street I was called back into the shop where they had found on a top shelf this Cancionero songbook: http://www.allcollection.net/?cancioner ... ng11041430 .
Also see live-from-the-camino/topic357.html (from another gb!)
Enjoy!