Milford Sound is a fiord in the southwest of New Zealand’s South Island within Fiordland National Park, Piopiotahi (Milford Sound) Marine Reserve, and the Te Wahipounamu World Heritage site. It has been judged the world’s top travel destination in an international survey (the 2008 Travelers’ Choice Destinations Awards by TripAdvisor) and is acclaimed as New Zealand’s most famous tourist destination.

As a fiord, Milford Sound was formed by a process of glaciation over millions of years. The village at the end of the fiord is also known as Milford Sound.

Milford Sound runs 15 kilometers inland from the Tasman Sea at Dale Point (also named after a location close to Milford Haven in Wales)—the mouth of the fiord—and is surrounded by sheer rock faces that rise 1,200 meters or more on either side. Among the peaks are The Elephant at 1,517 meters, said to resemble an elephant’s head, and The Lion, 1,302 meters, in the shape of a crouching lion.

Milford Sound is home to a variety of marine mammals, including seals and the southernmost wild population of bottlenose dolphins. Whales, especially the humpback and southern right whales, are increasingly observed due to the recoveries of each species. Penguins are also common within the sound, which is a breeding site for the Fiordland penguin and has subsequently been identified as an Important Bird Area by BirdLife International.

Milford Sound attracts between 550,000 and 1 million visitors per year. This makes the sound one of New Zealand’s most-visited tourist spots even with its remote location and long journey times from the nearest population centers. Many tourists take one of the boat tours which usually last one to two hours. Tramping, canoeing, and some other water sports are possible. Milford Sound is also a destination for cruise ships.

The Milford Discovery Centre & Underwater Observatory is located in Harrisons Cove on the north side of the fiord. Situated within the Piopiotahi Marine Reserve, the underwater observatory allows visitors to view the fiord’s unique marine environment at a depth of 10 meters.

According to Wikipedia