At the listed co-ordinates you will find some information boards about the Otago Central Rail Trail. (This has been updated 15 May 2022 due to changes at the sign - the final remains at the same location)
You can find the information for the cache location here and you don't have to travel to find for the final.
S45 30.ABC E170 0D.EFG
A = number of plugs (electic sockets) - look up in roof space.
B = There is a six digit number on an orange tag inside the roof, third digit minus fourth digit.
C = The number of ways you can travel the trail based on the pictures at the bottom of the posters, plus one.
D = The name Middlemarch was applied to the post office opened in October 18D6.
E = On one of the board thee are several pictures of what you will see on the rail trail (including a bike). How many pictures are there on this board minus two?
[Looking at the back of the Middlemarch map board from the left, you will see behind down low a 6 digit green tag - starting 30xxxx.]
F = will be the fourth digit on green tag.
G = The fifth digit of the orange tag plus the third digit of the green tag minus 1.
Check sum = 37