This is a hilltop that I am fortunate enough to have access to via work. We have a land mobile repeater at this site to provide voice coverage for our staff in the field. This area is generally closed to visitors and trampers due to a rare frog living in the area. You may be able to convince DoC that you will take the necessary precautions however so dont let me put you off.
DoC article here https://www.doc.govt.nz/parks-and-recreation/places-to-go/waikato/places/whareorino-conservation-area/
Contacts were short and quick due to me being at work but I managed to make 3 contacts on 2 metres and 3 more on 40 metres before packing up due to our taxi arriving soon.
Details
Summit – Maungamangero ZL1/WK-050
Height – 802 mASL
Access –Helicopter. There is an old track to the site but it has been closed.
Coverage – Cell coverage patchy but ok (spark). Good coverage into 720 and 7375 repeater.
Summit Marker – Trig + Radio Mast
Land Access Permission – DoC Permission required – will likely be declined.
NB: Photos are not for use elsewhere, without prior approval.