High above the Glow Worm Tunnel, hidden under the moss and by the bush are a series of brick and stone walls.
The walls were built around 1906 when the Wolgan Valley Railway was being developed.
They were built in a creek bed, apparently to stop rocks and other debris falling onto the railway line immediately below.
The brick wall at the cliff edge forms a small reservoir. It is strong enough to catch large tree trunks washed down the creek. The stone walls a few metres further up the creek bed are massive, built to last. They block about 85% of the width of the creek. The gap was left intentionally and was built square.
Ben Bullen 8931-4S
Wollemi National Park (NSW)