Ohinemuri Regional History Journal 48, September 2004

EDITOR'S NOTE: A document has been produced by Eric Lens following his research into the area known as Union Hill at Waihi. The document contains historical material collected, together with the results of a ground survey.

Following is the Introduction to the document. The Editor thanks Mr Lens for making this available for publication in the Journal.


By Eric Lens

Union Hill is a remarkable heritage area within the Waihi urban area. Mature pine and wattle tees, and a variety of native species, disguise a rich and colourful past.

Several layers of gold mining activity exist on Union Hill, from the first prospecting in the early 1880s, the scavenging operations of Mineral Resources and their processing plant, to the present Waihi Gold Mining Company operations (and more in between).

The base of Union Hill was the site of the "Waihi Battery" (also known as "Waihi Mill", the names used interchangeably in the historical literature), at one time the largest gold and silver processing mill in New Zealand. Construction of the Waihi Mill commenced in 1888. The hill itself was extensively mined bu a succession of mining concerns.

The first ore roasting kilns on this site were the first to be built on the Hauraki goldfield. The group of ten (perhaps more) that still exist, in remarkable condition, are unsurpassed (the Victoria Battery site at Waikino has only five open kilns {eight were constructed}).

The six air-agitation tanks (also known as B&M, cyanide, Pachuca, conical or tall tanks) are, I believe, the only air-agitation tanks to be built of concrete, and the only air-agitation tanks still in existence today (in New Zealand).

The Waihi Battery

The Waihi Battery

Union Hill Waihi
Ohinemuri Regional History Journal 48, September 2004
The Waihi Battery

The Waihi Battery, at sixty stamps, was the largest in New Zealand at the time; likewise when it was enlarged to ninety stamps. Much of the foundations of the stamper buildings and engine house still exist.

The Smelthouse and Refinery operated for the life of the Waihi Battery, and the Victoria Battery. Virtually the entire bullion production of the Waihi district passed through this facility.

The Old Union No. 1, the New No. 1, and the Mascotte shafts are open and visible. The New No. 1 Shaft retains now rare winding engine-room remains. Numerous adits are to be found on the hill, with perhaps the most notable being the Amaranth.

Together with many other concrete buildings and foundations, a wonderful opportunity for interpretation of this site exists. The heritage value to Waihi is immense.

All this within a wonderful wilderness area of great recreational potential.