I've been researching my Scots-Irish ancestry in Ulster, which reminded me about the unusual political and geographic situation in County Donegal. Ulster is one of the provinces of Ireland, but it includes the six counties of Northern Ireland/United Kingdom (Antrim, Armagh, Down, Fermanagh, Londonderry, and Tyrone) as well as three counties in the Republic of Ireland (Cavan, Donegal, and Monaghan). Wikipedia says, "Ulster has no official function for local government purposes in either jurisdiction."

The situation is well-summarized in the 'Irish Ancestors' section of The Irish Times: County Donegal is something of a geographical and political anomaly. It is the northernmost county on the island, has its strongest cultural, commercial and ethnic ties with neighbouring areas  of Northern Ireland, yet forms part of "the south," the Republic of Ireland. The climate and terrain have more in common with Scotland than with southern counties. The western and northern coasts have been worn into jagged bays and fjords by the full impact of the north Atlantic and the magnificent barren inland mountains - Errigal, Dooish, Blue Stack, Slieve League - form part of the same geological structure as the Scottish highlands.

According to Wikepedia, much of County Donegal is "seen as a bastion of Gaelic culture and the Irish language, the Donegal Gaeltecht being the second largest in the country." 'Anomaly' does seem like a good way to describe it.