Mordor and Emyn Muil

Tongariro National Park comprises the area around the three big central North Island vulcanoes: Mt. Ruapehu, Mt. Tongariro and Mt. Ngauruhoe. About half an hour's drive south of Taupo, at Turangi, turn off State Highway 1 and follow SH 47, which keeps to the right of the mountains. A good half an hour further on, a road turns off towards "Le Chateau", one of New Zealand's poshest hotels. The Tongariro crossing, a one day walk, starts here - I didn't have a chance yet to try it, but will report back when I have!

Driving up to the topmost parking space, you'll see several service/restaurant buildings at its top side, and to the left of them there is a path leading around the top of a skilift. Follow that path until you reach an area of tumbled rock, and keep fairly straight ahead from there, walking towards the steep incline that towers over the area - there is a fairly clear path leading in that direction. Having reached the foot of the incline, you'll notice a small concrete platform - if you turn to the left from there, and slightly downwards, you'll end up at the place where Elrond stood in the battle of the Last Alliance (that is, in the film's prologue) - overlooking a mountainside with loose rocks.

If you turn right from the concrete platform, and follow the path to the remarkable, rugged mountain crest, you'll end up in the very place where Frodo and Sam were loosing their way in the Emyn Muil. A little further on is a dell, which, I suspect, served for the scene where Gollum crawled down the rockside towards the two sleeping hobbits (although I am not really sure it really is the place - it does look similar, though!).
In any case, the area was evidently used not only for the scenes on the slopes of Mount Doom (as claimed in the Locations guidebook), but also for the Emyn Muil. This was very obvious especially in the weather conditions I encountered: it must have been very similar conditions when they shot those Emyn Muil scenes! Makes you feel for the poor actors, really...