Cache is up a 4wd track but have seen 2wd cars up there.
The Ahuriri Conservation Park has over 49,000 hectares of rugged mountain country, valuable and vulnerable wetlands, tussock lands and beech / tawhai forest.
http://www.doc.govt.nz/Documents/parks-and-recreation/places-to-visit/canterbury/twizel/ahuriri-conservation-park.pdf
Cahe is a 300ml with logbook.