Home to the south western section of the snow capped Southern Alps, numerous sounds and steep valleys and deep lakes, Fiordland is the absolute must see natural attraction.
Due to its extreme isolation and inaccessibility, most of the National Park is in a pristine state. The area is home to threatened native bird species such as the flightless takahe, the kiwi and the blue duck.
Milford Sound is the absolute star and gets all the publicity but Doubtful Sound is much larger and has more branches but suffers due to the lack of inaccessibility. It is the site of several large waterfalls including Helena Falls at Deep Cove. You'll find the requisite penguins and sea lions milling around but there are even humpback whales, orca and killer whales. It is also the base of the Manapouri Power Station, the largest hydroelectric plant in New Zealand.
Above Doubtful Sounds, lies Browne Falls. A candidate for the highest waterfall in the country at over 600m high. Set amongst unforgettable scenery amidst dense rain forest, this is something to behold. The other candidate is Sutherland falls which can be viewed as part of the Milford track.
This part of New Zealand has a very wet climate, receiving 6,300mm of rainfall per year. Consequently Fiordland is also home to three of the country's deepest lakes. Lake Manapouri, Hauroko and Lake Te Anau. Two of New Zealand's great tracks start at Lake Te Anau – the Milford Track and the Kepler Track. Be sure to check out the limestone caves on the western shore.
The National Park is world heritage listed and is on many of the must do lists in world travel.