Derry, or Londonderry depending on who you ask, is the only city in Ireland that still has its complete medieval-style walls. They were built between 1613 and 1618 by London guilds as part of the Plantation of Ulster, and they run for about a mile around the old town, wide enough to walk along and studded with cannon. During the Siege of 1688 and 1689, thirteen apprentice boys shut the gates against a Catholic army, and the city held out for 105 days, which is a story still told with strong feeling on both sides.
Later history was harder. In 1969 and 1972 the Bogside district below the walls was the stage for the Battle of the Bogside and Bloody Sunday, and the murals there, painted by local artists, are part of how the city remembers those years. It would be wrong to treat any of it as a tourist sideshow. The Peace Bridge, opened in 2011, curves across the River Foyle between the two sides of the city, and a visit to the Guildhall, with its stained glass and big clock, tells a more cheerful story of modern Derry.
For a rider the main thing to know is that Derry is the end of the Causeway Coastal Route and a gateway to the Atlantic coast beyond. A few miles to the east, the A2 runs along Lough Foyle toward Limavady, with the basalt cliffs of Binevenagh above, and then the Downhill Strand and its clifftop temple. West is Donegal and the Wild Atlantic Way, which would take another few days to do properly. The roads are wide, usually well surfaced, and the wind off the sea can be strong.
Derry is a city of well over eighty thousand, so there is no shortage of fuel, food and bed. The walled town has pubs with live traditional music most nights, and the cafés near the Guildhall do a good strong tea. Parking on the street within the walls is limited, so use a car park on the edge and walk in. Take time to walk the full circuit of the walls before you go.