All new buildings have wheelchair access, and even hotels in grand old country houses often have lifts, ramps and other facilities. Hotels and B&Bs in historic buildings are often harder to adapt, so you'll have less choice here.
Modern city buses have low floors for easy access, but few have conductors who can lend a hand when you're getting on or off. Many taxis take wheelchairs, or just have more room in the back.
Download Lonely Planet's free Accessible Travel guide from http://lptravel.to/AccessibleTravel.
A directory of accessible venues in Northern Ireland can be found at http://adaptni.org.
Disabled Go (www.disabledgo.com)