Derry

Derry takes 1 day to see: walking atop the 17th-century walls, the only ones in Ireland that surround the city completely and intact, and crossing the pedestrian Peace Bridge over the River Foyle are the main reason to visit. April-September is best. It's inexpensive by British standards. It's Northern Ireland's second city and a central point for the murals and history of the conflict known as «the Troubles», with guided tours explaining the 1972 Bloody Sunday in the Bogside neighborhood.