Knapsack Reserve & Knapsack Viaduct

This map was created using GPS Visualizer's do-it-yourself geographic utilities.

Please wait while the map data loads...

Route: Moore Street, Knapsack Reserve, Elizabeth Lookout, Knapsack Viaduct, Siding Lookout, Lapstone Zig Zag Walking Track, Lucasville Station, Knapsack Street, Mountains Trail, Knapsack Gully, Moore Street

Date: 12/04/2025
From: Moore Street, Glenbrook

Parking: Moore Street
Start Point: Moore Street
Finish Point: Moore Street
Region: Knapsack Reserve

Route length: 8.3 km
Time taken: 02:02
Average speed: 3.7 km/h
Ascent: 330m
Descent: 318m

Knapsack Reserve, located at the foot of the Blue Mountains, has a variety of trails that centre largely around its historic sandstone viaduct. This hike, starting from Moore Street and heading to Elizabeth Lookout and the viaduct, is fairly straightforward, taking you through some lush woodland, past historical landmarks, and up to a beautiful viewpoint. Being a reserve, it's dog-friendly too, so pooch can join in with the adventure.

We started our hike from Moore Street in the village of Glenbrook, where there's plenty of street parking available. While Moore Street is a convenient starting point, there are several other entry points into Knapsack Reserve, each offering different routes to key landmarks like the viaduct and Elizabeth Lookout. One notable option is Lovers Walk—one of the few officially named tracks in the reserve—which provides a scenic and well-marked alternative.

The beginning of the trail is easy to spot, and as you set off, you're quickly enveloped by dense bushland. The first stretch is relatively flat, making for a gentle start to the hike. The path loosely follows Knapsack Gully, though you'll notice a network of intersecting trails along the way. Most of these are unnamed and frequently used by mountain bikers, so it's worth staying alert. We continued east toward Elizabeth Lookout, enjoying the peaceful surroundings and occasional glimpses of the gully below.

Heading out from Moore Street

Knapsack Reserve

Perched on the edge of the Blue Mountains escarpment, Elizabeth Lookout offers sweeping views across Western Sydney and the winding Nepean River below. Named in honour of Queen Elizabeth II, it’s the best vantage point within Knapsack Reserve. The expansive outlook and clear skies made it an ideal spot to launch my drone, capturing even more of the landscape’s grandeur.

Elizabeth Lookout

Elizabeth Lookout

The lower escarpment of the Blue Mountains

The two viaducts over Knapsack Creek

New Knapsack Viaduct and the M4 Western Motorway

Knapsack Viaduct

Western Sydney

The next stop on the hike is the striking Knapsack Viaduct, a historic sandstone structure that spans the narrow depths of Knapsack Gully. From Elizabeth Lookout, the trail descends steeply—dropping around 150 metres through rugged terrain as you make your way down towards the gully floor.

Heading down towards the viaduct

Knapsack Viaduct

The sandstone arch viaduct was originally constructed to carry the Main Western railway line across Knapsack Gully. It formed part of the pioneering Lapstone Zig Zag—an engineering marvel of its time and the first zig zag railway built on a main-line anywhere in the world. This innovative design allowed trains to ascend the steep eastern escarpment from Emu Plains to what is now Glenbrook, overcoming a previously impassable gradient. Opened in 1865, the Zig Zag operated for roughly 30 years before being superseded by a more efficient tunnel system at Glenbrook.

A "zig zag" refers to a clever railway design used to navigate steep gradients. Instead of a continuous uphill track, the train follows a series of reversing switchbacks—moving forward, then backward, in a zigzag pattern up or down the slope. This method allows trains to climb challenging terrain without requiring long, winding routes or costly tunnels.

The Zig Zag Railway at Lithgow is a prime example

Knapsack Viaduct

Knapsack Viaduct

Continuing along the trail, the route crosses the historic Knapsack Viaduct, which once carried trains across the gully and later served as a road bridge. Today, it's reserved for pedestrian use only, offering a unique opportunity to walk across this impressive sandstone structure. At the far end of the viaduct, a steep staircase leads upward, climbing back toward the old Lapstone Zig Zag railway alignment. The ascent brings you to Siding Lookout, a vantage point along the original track.

Crossing Knapsack Viaduct

Knapsack Viaduct

Constructed in the 1860s, the railway played a pivotal role in opening up the Blue Mountains region to development and settlement. Today, remnants of the original line are still visible, including hand-cut stone cuttings, embankments, and sections of the old track bed. The former rail alignment has been repurposed as a tarmac walking path, allowing visitors to trace the route once taken by steam locomotives as they climbed the escarpment.

Further along the path, you'll come across the former site of Lucasville Station. Although the station buildings have long since disappeared, the original platform still stands—a quiet reminder of the area's railway heritage. Nearby, rock-cut steps lead up to the grounds of Lucasville, the country estate of politician John Lucas, who personally requested the station's construction to serve his guests and residence.

Lucasville Station

The Zig Zag railway points

After passing Lucasville Station, the path continues through an impressive rock cutting situated above a former quarry site. This section leads to the end of Knapsack Street, where a small number of car parking spaces are available. Before Knapsack Street intersects with the A32 Great Western Highway, it passes the main entrance to RAAF Base Glenbrook, home to Headquarters Air Command. The base occupies the site of the former Lapstone Hotel, which was sold after World War II due to declining popularity.

Zig Zag rock cutting

A narrow path threads its way between the Great Western Highway and the perimeter fence of RAAF Base Glenbrook, leading through bushland to an area of scrub—the site of the former water treatment works. Here, you'll find the western entrance to the Lapstone Hill Tunnel, now blocked off but steeped in history. Constructed between 1891 and 1892, the tunnel was repurposed during World War II to store mustard gas, and later served as a mushroom farm. Today, restoration efforts are underway to reopen the tunnel for public recreation, adding another layer of accessibility to this historically rich area. From here, the path loops back to Moore Street, completing the circuit.

The western tunnel portal