A blind man rests in a niche at Maryam Wukro, one of the oldest rockhewen churches in Tigray, the heartland of ancient orthodox Christianity in Ethiopia. Intricately hollowed out by hand from solid rock, the cavernous interior provides a cool spiritual respite for pilgrims from villages far in the valley below. Most of the churches in the north date back to the 6th century AD but some, like Maryam Wukro, are thought to be older still, their origins lost long before the birth of Christ.