Belfast is the capital of Northern Ireland, a region that has seen more than its share of unrest almost since its creation in 1921. The Roman Catholic and Protestant populations have a history of being at odds over whether Northern Ireland should be part of Ireland or part of Great Britain. The sides are called "nationalist" and "unionist" respectively. Most recently, the conflict took the shape of what's called the Troubles, the period of time ranging from the late 1960s to the late 1990s. Since the Good Friday Agreement of 1998, however, the violence has decreased substantially and Belfast (and Northern Ireland as a whole) is seeing a dramatic increase in tourism.
What to do
To get an up close and personal look at what's left of the political conflicts in Belfast, don't miss out on a Black Taxi Tour - you can book them through all hostels and hotels, and you'll be getting a private guided tour of the more important points in the history of the fighting. One of the things you'll likely see plenty of on your tour are the political murals around the city - they're a signature of Belfast, and an indication that despite today's peace, the sentiments behind the previous violence still exist.
Ulster Museum has a large section devoted to the history of the conflicts in Northern Ireland, but it's closed for a major redevelopment until 2009. Among the more odd things to do and see in Belfast is the Titanic Boat Tour - the doomed ship was built in Belfast - and the Botanical Gardens, including its collection of carnivorous plants.
Above all, don't forget to enjoy a pint of Guinness in what some say is Northern Ireland's most beautiful pub, the Crown Liquor Saloon on Great Victoria St. Even if you don't imbibe, you'll have plenty of atmosphere to drink in!