An historic abandoned viaduct and zig zag on part of the first railway line constructed over the Blue Mountains.
The former railway route adopted involved an impressive sandstone viaduct over Knapsack Gully. The viaduct was the largest in Australia, being 388 feet long and 120 ft high with 5 spans of 55 ft and 2 of 20 ft.
Construction commenced in 1863. The line was opened to Weatherboard (now Wentworth Falls) on J Originally built to carry a single railway track, the bridge was later fitted with a new concrete deck, enabling it to carry 2 lanes of road traffic. It formed part of the Great Western Highway until being by-passed in the mid 1990's. Today it is used only by pedestrians, bicycles, emergency vehicles, & the Olympic Torch Relay.
Photo credit: Rail Trails Australia. For more information and a location map please visit RailTrails Australia.
- Coarse gravel
- Flat to slight incline
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Total distance: 2976 m
Max elevation: 169 m
Min elevation: 88 m
Total climbing: 159 m
Total descent: -158 m
Getting there
Getting to the trailhead: Knapsack Reserve.
Knapsack Viaduct is signposted from the M4 Motorway/Great Western Highway at the Emu Plains exit. From the car park at the junction of the old highway and historic Mitchells Pass, a concrete footpath rises gently and follows the former railway and highway route to and over the viaduct. From here, dirt paths (suitable for walking only) descend below the stone arches or climb to Elizabeth lookout, upper Zig-Zag ‘roads’ and Lucasville station.
Closest towns to this walk: Blaxland, Glenbrook, Lawson, Springwood, Wentworth Falls
About the region
An 634 metre-long 1892 tunnel, which bypassed the Zig-Zag, is located mainly south of the Great Western Highway. The tunnel is not open at this stage but Blue Mountains City Council are working on reopening it for cyclists and pedestrians. The entrances to the tunnel can be reached by walking tracks. The eastern entrance can be reached via a tunnel beneath the M4 to Governors Drive and then a track (overgrown at times) from near a water tank. The western end can be reached from the top of Tunnel Gully on the northern side of the Great Western Highway. Once closed in 1913, the tunnel was at times used to house a mushroom farm and to store mustard gas.
Similar walks nearby
Looking for more walks in or near Knapsack Reserve? Try these trails with a similar difficulty grade.
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Track grade
Grade 2 (Easy) -Â
A Gentle Introduction to Inclines: Grade 2 on the
AWTGS represents easy walking tracks that offer a slightly more challenging experience compared to Grade 1. Similar to Grade 1, no prior bushwalking experience is required. The track surface is typically hardened or compacted and may have gentle hill sections or occasional steps. The total distance of a Grade 2 walk is typically no greater than 10 kilometers. These walks are still suitable for families with a bit more experience or those seeking a gentle introduction to some inclines.
Explore safe
Plan ahead and hike safely! Carry enough water, pack layers for changing conditions, and bring safety gear like a torch, PLB, and reliable communication device. Check official sources for trail updates, closures, and access requirements, and review local weather and bushfire advice. Most importantly, share your plans with someone before you go. Being prepared makes for a safer and more enjoyable hike! Stay Safe, Explore More, and Always #ExploreSafe.
Packing checklists
What you carry in your pack depends on factors like weather, terrain, and your adventure type. Not sure what to bring? My free planning, food, and packing checklists are a great starting point, covering day hikes, overnight trips, and multi-day adventures. Use them to customise your kit and always prioritise safety.
Let someone know
Before heading out, take a moment to fill out your trip intentions form. It’s a quick way to share your hike details with family or friends. If something goes wrong, they can notify emergency services, ensuring a faster response and peace of mind. Stay safe and enjoy your adventure
Suggest an edit
Spotted a change on this trail? Maybe there are new features, the route has shifted, or the trail is permanently closed. Whatever the update, I’d love your input. Your feedback helps fellow hikers stay informed and ensures that our trail info stays fresh and reliable.
10 Reviews on “Lapstone Viaduct & Zig Zag Walk (3km)”
Can you please post some Victorian walks? ??