Best Astronomical Architecture

History is sometimes full of fascinating, mysterious examples of thought-provoking ingenuity, sometimes beyond sensible comprehension. Astronomical architecture has been around for unconscionable millennia. Stonehenge springs to mind, dating back to the Stone Age, along with some enormous structures in South America and other far-flung places that are aligned with the sun and stars for some particular event.

The designed alignment of structures so that the shadows cast at sunrise or sunset on particular days of the year are phenomena usually associated with pagan practices, not so much Catholicism. When I came into the monastery village of San Juan de Ortega in Rioja, Spain, I was struck by the enormity and age of the former monastery church. Its unique and interesting architecture is quite remarkable on its own. Juan de Ortega, the story goes, was an engineer/monk of the early 12th century who built bridges and roads for pilgrims on their way to Santiago in addition to building this church and hospice for pilgrims. It's a common enough story along the Camino. The monastery served its purpose during the Middle Ages and dwindled during the Age of Enlightenment, like so many, until the sitting government of the early 19th century sold off church property and let it drift into ruin.

The astonishing part of this particular tale comes in 1973 when a scholar made some measurements and discovered that on the spring and autumn equinoxes, late afternoon sunlight comes through a small window and, in a sweeping arch, progressively illuminates the three sections of the top of one column where the Biblical passages of the Annunciation, the Nativity, and the Adoration are carved.

The church, along with San Juan's ornately carved tomb in the crypt, has since been restored and part of the former monastery has been transformed into a modern pilgrim house. The warm tradition of the resident priest making a simple garlic soup for pilgrims is widely known on the Camino, but when I arrived, the pilgrim house was closed and the priest wasn't around. The church was fortuitously unlocked, though, and I spent a fair amount of time there on a beautiful sunny day in early February.

Even though I stood before the column many weeks before the spring equinox, and thus missed the phenomenal illumination, I was still amazed by two things - first, that the 12th-century architect - was Juan on his own? was he under the instruction of an abbot or king or someone? maybe, maybe not, who knows - would design this pagan-ish feature into the church for the purpose of Christian devotion, and second, that this spectacular, beautiful, intellectual feature needed to be rediscovered in the late 20th century. How could this be? Was the equinox illumination a big secret when it was built or was it widely known? It's easy to speculate that if it were a fact widely known, it would have been documented all over Europe by the multitude of pilgrims during the Middle Ages... maybe it was only known by the subsequent abbots or other monks for their personal contemplations. Could it have been that the architect/sculptor/engineer never even told anyone?

The feature was built centuries before Copernicus, et al. and the other Renaissance geeks who developed complex measuring devices for scientific application. Many post-Renaissance churches I've seen, mostly in Italy, have small portholes on the south walls and curved meridians on the floors that allow the calculation of a date for Easter - traditionally the first Sunday after the first full moon after the equinox - but these were clearly built as calendar tools and centuries after San Juan's. San Juan's church has this special feature only to draw attention to one specific carving among dozens depicting important Biblical passages.

Juan was a contemporary of Dominic de Guzmán, born and educated nearby, who founded the Dominican Order and eventually became a Saint - the patron Saint of astronomers, oddly enough. Pretty thought-provoking. If this one church built to help pilgrims in the 12th century had such a 'undiscovered' feature, do other churches have astronomical features, too? Did Dominic, something of a brainiac, have an influence in Juan's design? Would the secret illumination design only be associated with equinoxes and solstices, or could there be solar alignments designed to reveal something special on the churches' patron Saints' days?

When I stood there, I thought of Saint Michael. In my extensive travels through Europe, I've seen loads of Saint Michael churches, each one, it seems, built on the highest point around - he was after all the Archangel and generally depicted as an over-muscled Adonis with beefy masculine wings and wearing a short toga. His feast day is September 29th, not far from the autumnal equinox. With these churches always being the highest structures around, it seems logical that the knowledgeable design team would integrate some solar illumination feature into them if they were going to do it anywhere.

I really enjoyed seeing the church at San Juan de Ortega and learning for the first time of the remarkable astronomical feature it contains - I don't carry a guidebook, so was completely and delightfully surprised by it. The church has always been on the trail to Santiago, but now is a pilgrim destination in its own right. Huge crowds apparently gather on the 21st of March and 22nd of September to witness the 10-minute-long solar spotlight on the carved Biblical passage. Wild stuff. I'll be sure to look more closely at churches built during this time period, especially if there's a connection with St Dominic. San Juan de Ortega is an outstanding example of Best Astronomical Architecture that I saw on the pilgrimage.