Around the 1850's the Yarra river bed underwent alluvial mining since it was known to have carried good gold. Sluicing was the most common practice for finding gold (using running water to breakdown gold bearing earth) however the strong and deep water flow was considered an issue. In around 1864 the Yarra River was diverted through a hand dug tunnel at the narrowest point of a rocky hillside, known as the Big Peninsula tunnel. This diversion allowed miners to continue to mine the river without concern for deep water, or strong currents.
The tunnel itself is approximately 2 meters wide and high, and about 25 meters long. Given the tools available at the time it is an incredible feat of ingenuity and no doubt required a fair amount of ‘elbow grease'. The image below is taken just after the outlet of the Big Peninsula Tunnel. Due to having the family and kids with me I did not have enough time to go for a hike to see the inlet, although that will hopefully be my next trip.
The Big Peninsula tunnel is located approximately 80 km's east Melbourne, on Woods Point Rd. and is around 14 km's East of Warburton. Access can be obtained at Peninsula Road, McMahons Creek, Victoria, Australia
Bear in mind that unless you are heading to the Little Peninsula Tunnel, stair access is needed so it is not pram or wheelchair friendly.