Per dictionary.com through the reference page:
Caledonia,
Roman name for that part of the island of Great Britain that lies N of the firths of
Clyde and Forth. The name first occurs in the works of
Lucan (1st cent. A.D.) and has been used in modern times rhetorically and poetically to mean all of Scotland or the Scottish Highlands.
But I do like the sound of it, and like callie as a NN