Visit the Passo delle Streghe

The oldest of San Marino’s three towers, an 11th-century fortress on Monte Titano with views to the Adriatic.

Second tower on Monte Titano’s highest summit, home to the ancient-arms museum.

Storybook fortress on a rock island ringed by a river canyon.

Island castle at the meeting of three sea lochs — Scotland’s most photographed.

One of Europe’s largest castle ruins, sprawled across a travertine hill.

Sweeping views from the mountain.

Rolling hills of honey-stone villages — Bibury, Bourton-on-the-Water, Castle Combe — that look unchanged in 300 years.

England’s chalk-white front door: cliff-top paths above the Channel with France visible on a clear day.