The wireless station on the Tinakori Hills (Mt Etako) overlooking Wellington was officially opened on 14 October 1912.
The site was some 300m above sea level, and, occupying about 8 hectares of Maori land, had to have a special access built for it. The radio aerial was supported by two masts of Oregon pine, 45m high and 90m apart.1

Photo: Sydney Charles Smith, NZ Graphic, 23 Oct 1912.
Sir George Grey Special Collections, Auckland Libraries

Photo: Sydney Charles Smith, Alexander Turnbull Library
This page has two original news reports of the opening of Wellington Radio’s station on Tinakori Hill (Mt Etako) – the first from a local newspaper, and the second from the Press Association.
Evening Post, 14 October 1912, p 8

Schaef Photo, Auckland Weekly News, 24 Oct 1912.
Sir George Grey Special Collections, Auckland Libraries
Wanganui Chronicle, 15 October 1912, p 8
Notes
1 Wilson, A.C. (1994). Wire and wireless: A history of telecommunications in New Zealand 1890-1987, (p 96), Palmerston North, New Zealand: Dunmore Press.