Saint Samaan The Tanner Monastery is a complex of Coptic churches built into caves in the Mokattam hills. The largest cave church is the main draw, but the approach through the Zabbaleen area is part of what makes the visit memorable.
It is not a casual walk-up sight from central Cairo, so plan transport and timing. For visitors interested in Coptic Cairo beyond the standard old-city churches, it is one of the city's most unusual religious sites.