Fiordlands is inextricably bound up with water and the fact that it has so much of it.  On the macro-scale, Fiordlands is even more affected by water in a solid form: ice and glaciers.  The very fact that it's called Fiordlands is a result of it's fiords being cut by glaciers.  The same goes for it's massive mountain valleys.  Valleys are often cut by rivers and these valleys tend to have a V-shape.  When a valley has been glaciated it acquires a classic U-shape like...well, like you see above.  This valley really is a poster-child for how glaciers change the landscape.

This a a view to the east overlooking Lake Katherine.  Henry Saddle is to the right, beyond the valley wall.  The picture above shows the valley shape better than a similar picture below, but the light in this picture is too pretty not to include.