Milford Sound Underwater Observatory,
Fiordland, New Zealand

personal experience...

I have been visiting Fiordland since 2004, but have not had the chance to check out the observatory until just a few years ago, and I was impressed!

the special fiordland ecology...

The ecology of the New Zealand fiords is often considered to be unusual. This is due to the high amount of rainfall leading to a relatively freshwater layer atop the salt. This has the effect of bringing some normally deeper water marine organisms higher up in the water column. The most important example is a type of Black Coral. Of course, the water is cold and the area is remote, so snorkelling and diving is not usually offered. But there is way of checking out what lives underneath the water...

the observatory

There is a small underwater observatory at Harrison Cove, within Milford Sound, Fiordland. By walking down several flights of stairs, visitors can go 'underwater' several metres and see the invertebrates and fish that live here.

'Black Coral' has white tentacles...(Damon Ramsey)

Eleven-armed Sea-stars suck against the window...

An Eleven-armed Sea-star. Go on - count 'em (Damon Ramsey)

and various species of fishes...

Scarlet Wrasse, Milford Sound (Damon Ramsey)
‘Butterfly Perch’, Caesioperca lepidoptera, Milford Sound (Damon Ramsey)
Banded Wrasse, Milford Sound (Damon Ramsey)
leatherjacket (Damon Ramsey)

access

I guess this is one of the most inaccessible observatories in the world! It is located in Milford Sound, in remote Fiordland in remote New Zealand! You can't drive to it; it can only be access by boat. Several of the day boat tours around Milford Sound pop in. Occasionally an expedition ship goes there. To get to Milford is several hours drive down from Queenstown. There are many (very long) day tours that explore Milford Sound from Queenstown.