Heybeliada wears its history on two hills at once: a walled naval school campus on one, a shuttered Greek Orthodox seminary on the other. The second-largest of the Princes' Islands, it rose from the Sea of Marmara as a pine-covered ridge that Byzantine monks, Ottoman naval cadets, and summering Istanbul families each claimed in turn. The Theological School of Halki, founded in 1844 on the grounds of the far older Monastery of the Holy Trinity, trained Orthodox clergy until it closed in 1971; its buildings and celebrated library still stand under monastic care. Cars never took the island — quiet is its oldest custom.
You arrive by ferry at a small waterfront of fish restaurants and cafes, then climb. The pace stays slow: bicycles, walkers, the hum of an electric minibus. Pine needles soften the paths; the air smells of resin and salt. Trails lead to pebble swimming coves, past the summer house kept as a small museum to İsmet İnönü, and up the Hill of Hope, where the seminary's red-roofed courtyard looks out over the Marmara. Today Heybeliada is a day-trip refuge — emptier than neighbouring Büyükada, and, for many, the more restful for it.