This bloke can be a bit heavy on the "good Kiwi joker" routine for my liking (he's a North Islander) but the video, which has some amusing bits, will give you a pretty good idea what to expect foot hunting for Thar. The Landsbrough Valley is situated along the main divide between the Mt Cook and Mt Aspiring national parks. Not somewhere you'd want to go if you don't like heights. You don't have to go this extreme to be successful but if you want there's plenty of this sort of stuff out there.

https://www.youtube.com/watch?v=cT2vw2d0AMw