County Derry (Contae Dhoire or simply Doire in Irish) is one of the six counties of Northern Ireland, in the province of Ulster. It was named after its main town (later city and administrative centre), Derry or Londonderry.

Unlike the town, historically there was not a preceding County Derry, it was established in 1613 by combining the former County of Coleraine with small parts of Counties Antrim, Donegal, and Tyrone at the behest of the London companies (hence, London-Derry) so that they could control both banks of the mouths of the River Foyle and the River Bann and have access to sufficient wood for construction. The county town was Coleraine. As with the town, its name is subject to the Derry/Londonderry name dispute, with the form Derry preferred by nationalists and Londonderry preferred by unionists.

As you can understand, this is a pretty large undertaking which is why we will be adding buildings and places as we cover them. Currently we have the information on the following areas: