Whollyisland

There are several Holy Islands off the coast of Britain:

Lindisfarne, North-east England, home of a Dark Age monastery.
Holy Island, Anglesey, in North-west Wales, site of the port of Holyhead.
Holy Isle, Firth of Clyde, off the Isle of Arran, in Scotland.

There is also a Holy Island in the U.S. state of Massachusetts. The letter is said to have originated from "Boston (Mass.)"