This heritage library and Genealogy Centre, in the heart of the old walled city, can help you research your Derry roots. Derry was one of the main ports for the exodus of thousands of emigrants for the New World in the 18th and 19th centuries; records show that Ulster men and women became the second-most-numerous group in the colonial population and played an important role in the settlement of the West. Note: The center has few staff, so call ahead. Or, if you can't make it, check out their website -- it's one of the most useful Irish genealogy websites we've seen.