Located in the southwest area of South Island in New Zealand, Milford Sound is one of the country’s most stunning natural wonders. With sheer rock faces that rise roughly 1,200 meters above the water and a fiord that runs 16 kilometers to the open sea, the sights are incredible to behold. Interestingly enough, though it has been named the Milford Sound, it’s actually a fiord. It was misnamed due to its initial appearance, but a sound is formed when a river valley is flooded while the Milford Sound was actually created through erosion of ancient glacial ice.

Tomorrow's World Today Milford Sound natural wonder

The water in the fiord has a unique inky black appearance. This is partially due to the depth of the water, which is hundreds of meters deep, but it’s also because of the combination of freshwater and seawater. There are roughly six meters of freshwater sitting on top of ocean water. The area itself has the highest concentration of rainfall in New Zealand with a rough annual rainfall of 6,813 mm falling for 182 days a year on average. During the many rainfalls of the year, the water drains from the forests that surround the Milford Sound and a tannin is washed into the water which stains it, giving it a hue similar to strong tea.

Tomorrow'sTomorrow's World Today Milford Sound natural wonder

The dark hue of the water blocks out light and makes the area ideal for deep-sea life to thrive even in shallow waters. Because of this, the area has become home to a variety of sea life including bottlenose dolphins, native fur seals, blue ducks, and birds like the tapako, takahe, mōhua, and kea. Visitors to this natural wonder are able to see the sea life as well as the spectacular views through the Milford Sound Cruise or by hiking, kayaking, or visiting the local Underwater Observatory.