JUST OFF NE SANDY and 85th, beyond the lights of the Howard Johnson and the Quality Used Tires, you'll find the World's Largest Christmas Choral Festival. That's right: world's largest. Also, a shrine to the Virgin Mary that a Canadian priest carved out of the base of a 110-foot basalt cliff in 1923. Welcome to the Grotto, known in Catholic phrasing as the National Sanctuary of Our Sorrowful Mother.

I don't know how Catholics exactly measure the largeness of their choral festivals, but I do know that from the day after Thanksgiving until the day before the New Year (the Holy Weeks of Inescapable Nonstop Christmas, or HWINC), 164 choruses will perform at the Grotto, which also during HWINC features a petting zoo, a Christian-themed puppet show, and rather tasty hot chocolate for $2.50 a cup.

It also features a giant sculpted head of Jesus that, yes, I mistook for someone else and had to ask my tour guide, "Who's that? Lincoln?" But that's more my parents' fault, since they're the ones who raised me with too many young-adult historical fiction novels and too little religion.

Although the story of Portland's Grotto would make an excellent young-adult historical fiction novel.

Picture Ambrose Mayer growing up in the wilds of Berlin, Ontario, in the late 19th century, decades before the town would de-Germanize its name to Kitchener. Picture his mother lying near death as she gives birth to his sister. See Mayer promising God that if she survives, he will do great work for the church. His mother survives! Mayer becomes Father Mayer!

Chapter Two: The church sends Father Mayer to Portland, and in 1923, he talks Union Pacific Railroad into selling him 50-or-so acres of a woodsy former quarry. On an installment plan. A crew begins carving a cave out of the Rocky Butte basalt and installs a statue of the Virgin Mary. A year later 3,000 locals attend the Grotto's first mass. Postscript: The Grotto's 62 acres now include a botanical garden, chapel, and monastery with real live-in monks and nuns. They welcome 150,000 visitors a year. And they are worth $8.9 million.

(A quick history of weird Catholic grottos: Alexander Pope, the English Catholic famous for writing a bunch of poems I've never read, excavated a grotto beneath his mansion [named Twikenham in the English tradition of naming things ridiculously], inside of which he installed a camera obscura and reportedly remarked that, "Were it to have nymphs as well, it would be complete in everything." In 1912, a German priest in rural West Bend, Iowa, began a 42-year process of building the Grotto of the Redemption out of seashells, concrete, and precious stones. In Cullman, Alabama, a Benedictine monk built "Jerusalem in Miniature," a grotto filled with 125 miniature reproductions of famous churches and shrines. All of this makes Portland's Grotto seems downright normal.)

During HWINC, our own Sanctuary of Our Sorrowful Mother is bedecked with more than half a million Christmas lights. As I entered on a recent rainy Tuesday, neon silhouettes of Mary and angels burned out from a grove of dark cedar trees. I wandered past the petting zoo (70 percent goat, 20 percent miscellaneous,10 percent llama) and into a tent where I took in one of the 164 choruses performing beneath a banner for Standard TV and Appliance. And there at the center of the Grotto complex is the grotto itself, obscured during these weeks by an Italian-made nativity scene over which a massive Christmas star shines. Several hundred tall votive candles stand off to each side, their little flickering prayers shielded from the rain by wooden roofs.