Both Milford and Doubtful Sound are located in Fiordland National Park on New Zealand’s South Island. Milford Sound sits to the north of Fiordland and is the last fiord in the national park. Doubtful Sound, on the other hand, is located much further south and is roughly in the middle of Fiordland National Park. Milford Sound is easily the most visited place in Fiordland National Park and arguably the most beautiful and offers the widest range of experiences out of the two fiords. This makes Milford an easy front runner for those who love to personalize their experience and make it one the whole family will love. Doubtful Sound is a rather untouched paradise that’s off the beaten path. It’s an adventurous journey and one you’ll share with fewer people.