FactMilford SoundThursday, 1 January 2026
Milford Sound is misnamed — it's actually a fiord
A 'sound' is carved by rivers; Milford was gouged by glaciers, which makes it a fiord. The mistake stuck, so the national park was named Fiordland to set the record straight.
Early European settlers named Milford Sound before glacial geology was understood. Rivers carve sounds; glaciers carve fiords — with their trademark sheer walls plunging straight into deep water. Milford's walls drop over a kilometre into water up to 290 metres deep, unmistakably the work of ice.
The name was never corrected, but the surrounding park was pointedly named Fiordland National Park — today part of the Te Wāhipounamu UNESCO World Heritage Area. Rudyard Kipling, visiting in the 1890s, called Milford 'the eighth wonder of the world'.
Quick answers
- Is Milford Sound a sound or a fiord?
- A fiord. Sounds are river-carved; Milford was carved by glaciers, which is why the surrounding park is named Fiordland National Park. The original misnomer was never corrected.
Sources
- Milford Sound is geologically a fiord, carved by glaciers, within Fiordland National Park (Te Wāhipounamu UNESCO World Heritage Area). [source]