A county is a county is a county... not. The Local Government Acts of 1888 and 1972 created "statutorily defined administrative areas" and then "local government areas to be known as counties" closely based on the traditional designations. No modern maps look like the one below. For example, PGB is based in East Sussex in the southeast; note there is no such division here.

The six counties of Northern Ireland are not shown: Antrim, Armagh, Derry/Londonderry, Down, Fermanagh, and Tyrone.