Milford Sound / Piopiotahi is a fiord in the south west 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. Rudyard Kipling had previously called it the eighth Wonder of the World.
Milford Sound runs 15 kilometres 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 metres (3,900 ft) or more on either side. Among the peaks are The Elephant at 1,517 metres (4,977 ft), said to resemble an elephant's head, and The Lion, 1,302 metres (4,272 ft), in the shape of a crouching lion.
Milford Sound sports two permanent waterfalls all year round, Lady Bowen Falls and Stirling Falls. After heavy rain however, many hundreds of temporary waterfalls can be seen running down the steep sided rock faces that line the fiord. They are fed by rain water drenched moss and will last a few days at most once the rain stops.
With a mean annual rainfall of 6,412 mm (252 in) each year, a high level even for the West Coast, Milford Sound is known as the wettest inhabited place in New Zealand and one of the wettest in the world. Rainfall can reach 250 mm (10 in) during a span of 24 hours. The rainfall creates dozens of temporary waterfalls (as well as a number of major, more permanent ones) cascading down the cliff faces, some reaching a thousand metres in length. Smaller falls from such heights may never reach the bottom of the sound, drifting away in the wind.
Accumulated rainwater can, at times, cause portions of the rain forest to lose their grip on the sheer cliff faces, resulting in tree avalanches into the sound. The regrowth of the rain forest after these avalanches can be seen in several locations along the sound.