Details about the track can be found in this Marlborough Express article.
There were initially 12 caches in this series, however more are being added as the community gets involved in the project. This is the 19th in 'The Blairich Project series by Team W.A.S.P/the Seagnoid/taybeedragon, plus the is another seven in the Black Birch Series by bumandworker and Kiwimykl.
The cache is a plastic medicine bottle in a plastic medicine bottle.
Hope you enjoy your journey through this excellent project and as always, happy hunting.