Greencastle (Londonderry), Ireland

Beside the River Foyle in Northern Ireland, Derry is still surrounded by its seven-gated, 17th Century city walls. The spired St. Columb cathedral within the walls has exhibits about the extended siege the city endured in the 17th Century. The Peace Bridge is a modern monument to more modern troubles. The Tower Museum exhibits local history and affords views of the town and the red sandstone 1890 Guildhall nearby. On a hill outside the walls stands the 2,000-year-old Grianan of Aileach ringfort.