At each location there are some questions to answer, with letters replacing the numbers you need. Write down which numbers correspond to which letters, as you will need this information to decode the final location of the geocache. Note that you will have GPS issues at Q2 and Q3 because you are in an underground carpark, but I have provided instructions for how to get from location to location.
Q1 (the published coords): S 34 26.851 E 150 26.348 - Start here by the two large stone wheels. According to the plaque, the iron works on this site operated until which year = 18AB. Then proceed down the stairs to Q2.
Q2 (down the stairs): S 34 26.843 E 150 26.338 - This is a large display area at the bottom of the stairs from Q1. How many information boards are here = CD. Find the plaque marked "Rolling Mills at Work". How many iron footings still project up from the walls and edges of the long pit directly behind this sign? Answer = EF. Now look towards the far side of the carpark, to where the escalator and lifts are. Q3 is at the bottom of the escalator.
Q3 (bottom of the escalator): S 34 26.827 E 150 26.264 - At the bottom of the escalator is a glass cabinet containing some relics from the excavated site you just left. At bottom right is a furnace door marked with which year? Answer = 18GH. How many suspended glass shelves are in this cabinet? Answer = I.
Q4 (outside ALDI): S 34 26.864 E 150 26.396 - From Q3 take the escalator up, go forward then right and exit the centre via the main door. You should have GPS coverage now, but if not, turn to your left as you exit the centre and walk to the next building which is ALDI (past the Indian restaurant and across the driveway). At the front of ALDI is a plaque and some more relics in a cabinet in the wall. On the information board here are some photos from the Illustrated News in which year? Answer = 18JK. How many intact horseshoes are on display here? Answer = L.
To calculate GZ, refer to your values from A to L and perform the following calculation:
GZ = S34 2(B).(L+1)(E)(H-C) E150 2(B).(K-I)(J-B)(G).
You can check your coordinates on GeoChecker.com.
Good luck! I should note that this multi takes the place of a traditional cache placed near the downstairs exhibit by powerplayx2, which attracted 30 favourite points before it had to be archived. That cache was how I found this interesting area, and I have replaced it with this multi with their permission.
** Congrats to J+J.au and Baja.15 for FTF! **