The United Kingdom of Great Britain and Northern Ireland consists of England, Scotland, Wales, and Northern Ireland. The Isle of Man and the Channel Islands are British Crown Dependencies but are not part of the UK.
The diner inside is not as seen in the show, but the sign is still there and there's local history behind it. There are framed newspaper clippings and the menu acknowledges the show's three waitresses: Alice, Vera, Flo and the owner: Mel.
CBN.com - SUMMARY: Mel Gibson stars in SIGNS as Graham Hess, an Episcopal priest in a small Pennsylvania town who has lost his faith after a family tragedy and must protect his children from a mysterious creature who invades their farm.