Two men on a scaffold were working on, or perhaps touching up, a mural.

A priest, in white, stood at a lectern and read aloud from an illuminated book as a European video crew fussed with sound checks, then asked him, please, to start again. To an outsider the general impression was confusing, disconcerting. Can this newish, nondescript, somewhat disheveled, in-progress space really be the physical and psychic center of one the world’s oldest versions of Christianity?

The priest at the lectern burst into song, a long, gorgeous melismatic chant that bloomed in the dome. Everyone stopped to listen, enraptured. There was the answer. Yes, it can.

The evidence was even stronger outside. I was in Aksum just before an important holy day dedicated to Mary, the object of acute devotional focus in Ethiopian Orthodoxy. Pilgrims from far and near were already gathering, camping out in the park around the cathedral, prostrating themselves on its steps. A day later the city would be a sea of white, and St. Mary of Zion would be open, full and finished. People were the completing ingredient.

By the 10th century A.D. the long-lived Aksumite empire, once a rival to Persia and Rome, was out of steam, and the city itself a backwater. New rulers, known now as the Zagwe dynasty, appeared. They retained the distinctively Judaic form of Ethiopian Christianity, with its Saturday Sabbath and practice of circumcision, and further promoted the concept of an African Zion by giving it physical manifestation in a new capital city to the south of Aksum.

The force behind the new city was the 13th-century Zagwe emperor Lalibela, for whom the new capital eventually came to be named. He is credited — and here we are again in a tangle of fact, fantasy and informed surmise — with planning and creating the extraordinary group of 11 churches there, all chiseled directly from sandstone cliffs and gorges, that exist at Lalibela today.

According to legend the emperor himself, spelled by angels on night shifts, did the work, wrapping the whole job up in 20-some years. Whether or not the results can justifiably be called, as they often are, the eighth wonder of the world, they are certainly wondrous. And sharing, as they do, in a tradition of sculptured architecture that extends from Turkey to China, they are indeed world-spanning.