Which country is called sunset country?

There is no actual "Country" defined as a nation state with its own Government called "Sunset Country". There is however, a 100,000 square kilometer (60,000 square miles) area of the Canadian Province of Ontario called "Sunset Country". This region of Ontario is called this because it is the westernmost part of the Province and last part of Ontario where the sun sets for the day, hence "Ontario's Sunset Country".