The extensive ruins of Sumela Monastery, founded by Greeks in the 4th century, cling improbably to a sheer cliff, high above evergreen forests. This is one of the Black Sea region's unquestionable highlights. Ongoing restoration means you can't go inside until at least 2023, but for many visitors, just seeing the exterior from the 'Seyir Noktası' viewpoint at the lower car park is worth the 40km drive from Trabzon.
Climbing closer takes around 30 strenuous minutes on foot by a 1.2km zigzag footpath (no views) or 10 minutes by a 3km dolmuş hop (₺5 return). The latter passes a waterfall (700m) and a monastery viewpoint (2km) en route. From the upper car park, don't miss a 100m stroll to tiny Aya Varvara chapel. Inside the chapel, a video displays some of the monastery's murals and behind is another great view surveying the monastery complex through the trees. A boardwalk path leads 350m further to a ticket booth beside a restored historic aqueduct. Paying the ₺10 entry fee here allows you to climb some steps and walk 20m to an overlook from which you can look down on an archaeological site. That includes a colourfully fresco-festooned church apse, but don't expect to get inside or to see the main complex which, from this point, is hidden around the corner. Visit early or late to avoid the crowds of Turkish tourists.