Derry or Londonderry Irish: Doire Cholm Cille or Doire Calgaigh is the second largest city in Northern Ireland and is the fourth largest city on the island of Ireland. The population is 100,000. The city was founded in 542. It has old city walls which are still complete. The city is located near the border with the Republic of Ireland.
The city was originally called Doire (pronounced duhruh) which is an Irish word for a group of oak trees. In English, this word became "Derry". After the Ulster Plantations, the London Companies gave money for the building of the Port and Walls in Derry, and the city name was changed to Londonderry.
In 1984 the city council changed the name of the local government area back to its original title of Derry. But the City's official title is still Londonderry.
People from the Republic of Ireland call the city Derry, and so do people who want Northern Ireland to be part of the Republic of Ireland. People from Northern Ireland who want Northern Ireland to stay in the UK call the city Londonderry.