The approach to Egypt's Church of the Blessed Virgin atop Jabal al-Tayr (the Mountain of Birds), roughly 250km south of Cairo, once involved a perilous, vertical climb up a cliff rising straight from the Nile followed by a series of steep, rock-hewn steps. The handful of explorers to scale the mountain were intrigued by its mystical history. For centuries, the location – its current custodians explained to me – has produced untold miracles, even down to this day.