The Peninsula Tunnels are a pair of hand-dug gold-rush relics on the upper Birrarung (Yarra River) near McMahons Creek, about 15 kilometres east of Warburton. The Big Peninsula Tunnel was cut in 1864 by alluvial miners who diverted the river through the rock so they could work the exposed riverbed for gold — a square bore roughly two metres high and wide and about 25 metres long. The Little Peninsula Tunnel, a short drive west, was dug for the same purpose.
Both are reached from signposted car parks off the Warburton–Woods Point Road. The Little Peninsula Tunnel sits about 150 metres from its picnic ground, which has barbecues and tables — an easy stop with children. The Big Peninsula Tunnel is around a kilometre further on, a short walk from its own small car park.
For walkers, a 13-kilometre loop (moderate to hard, allow about four hours) links the area and passes scattered traces of 19th-century mining — water races, open cuts, shafts and small dams — through tall, damp forest. Take a torch for the tunnels, wear sturdy shoes, and expect the track to be slippery after rain.
The tunnels are in the Yarra Ranges National Park and open during daylight hours; check Parks Victoria for current track conditions before you set out. And remember, no dogs in National Parks.