The Troodos Mountains run down the spine of Cyprus, and in the eleventh century they were a refuge from the coastal raids that defined Mediterranean life. Monasteries went inland and uphill. Agios Nikolaos was built around 1100 near the village of Kakopetria, set in a clearing of pine and walnut along the Karyotis river. It is the only middle Byzantine katholikon - the principal church of a monastery - that still stands on Cyprus from that century. All sixty-five known Early Christian churches on the island had been three-aisled wooden-roofed basilicas, conservative in plan, slow to adopt the domes that Constantinople had been building for centuries. Architectural historian Charles Anthony Stewart attributes that conservatism to the independence of the Cypriot Church, which was self-governing and did not feel the need to copy fashions from the capital. Agios Nikolaos broke with that pattern. It is a domed cross-in-square, cousin to the great churches of Constantinople, planted in a Cypriot pine forest.

Walk inside and the walls argue with each other across centuries. The earliest surviving frescoes date to the eleventh century, painted soon after the church was built. The art historian A. H. S. Megaw saw in them "the deep-set staring eyes of the expressionist style" inherited from Byzantine miniaturists of the Macedonian Renaissance, the cultural revival that followed the end of iconoclasm in 843. A second campaign in the twelfth century, painted in the more sophisticated Comnenian style, suggests that masters trained outside the island, perhaps in Constantinople itself, had been brought in to refresh the walls. Most of what visitors see today, though, was painted in the fourteenth century. The Crucifixion and the Resurrection above the nave date to the late thirteenth or early fourteenth. Christ Pantocrator surveys the church from the dome. Sixteen prophets ring him at the drum. Four evangelists fill the pendentives. On the northwest pier, two enormous figures stand together: Saint Theodore and Saint George, both warrior saints, painted at life size.

Agios Nikolaos is one of ten painted churches in the Troodos region that UNESCO inscribed as a single World Heritage site in 1985. The grouping makes sense: these mountain churches preserve the most important cycle of Byzantine and post-Byzantine painting on the island, ranging from the eleventh through the seventeenth centuries. Most are small, most are tucked into villages or remote valleys, and most spent the period of Frankish rule - which began on Cyprus in 1192 under Guy de Lusignan, after Richard the Lionheart sold the island to him - as parish churches rather than imperial monuments. Outside the walls, the Frankish nobility built Gothic cathedrals in cities like Famagusta and Nicosia, sun-bleached now amid minarets and palms. Inside the mountains, Greek-speaking communities kept commissioning Byzantine frescoes long after Constantinople had fallen. The continuity, hidden under improvised pitched roofs, is what UNESCO eventually came to recognize.

There is something practical and a little stubborn about the second roof. Originally, Agios Nikolaos had no narthex either. The entrance porch was added in the early twelfth century, covered by a small calotte and two transverse arches, and at the same moment the steep timber-and-tile cover was thrown over the whole building. Snow accumulates in the Troodos. Roofs leak. Frescoes dissolve. The villagers who paid for the new roof did so because the church mattered to them and because they understood that art on lime plaster does not survive direct weather. Some of the original exterior masonry was hidden in the process, and a few interior paintings were lost when the church's appearance was altered later. The trade was a fair one. The dome under the hat is still there, the prophets still circle Christ, and the warrior saints still keep watch on the pier where the medieval painters left them.