In which country would you find “Milford Sound”?
Correct answer: New Zealand

Edward Sausage Finge
I've been there. To get there you drive through a tunnel bored at an angle of about 25 degrees downwards straight through a mountain and when you emerge it's like an ancient wet world completely different from the one you left minutes before .
Milford Sound is one of the wettest places in New Zealand so go prepared. Well worth a visit and tour on the fiord