View looking east towards Emu Plains. The 2nd Knapsack Viaduct consists of eight sandstone arches constructed in 1912. It is part of the railway line from Penrith to the Blue Mountains. Adjacent to it is the Lapstone Rail Bridge which one over the M4 motorway built in 1991. The Knapsack Gully bridge, with 7 arches, spanning Jamison Creek. Built by John Whitton it was used as a single railway track until 1913 when the Glenbrook deviation was built. The bridge reopened in 1926 to road traffic and closed in the 1990s, with the construction of the Lapstone extension of the M4.
