Windmill Hill Cutting is a large cutting on the dual gauge

Dual gauge

A dual-gauge or mixed-gauge railway has railway track that allows trains of different gauges to use the same track. Generally, a dual-gauge railway consists of three rails, rather than the standard two rails. The two outer rails give the wider gauge, while one of the outer rails and the inner rail...

 railway east of Toodyay

Toodyay, Western Australia

Toodyay is a town located in the Wheatbelt region in the Avon Valley, 85 km north-east of Perth, Western Australia. Toodyay is connected to Perth via both rail and road.-History:...

 in Western Australia

Western Australia

Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

. The cutting was constructed between 1963 and 1964 for the Eastern Railway route through the Avon Valley

Avon Valley, Western Australia

Avon Valley may refer to:* the fertile land in the catchment of the Avon River * the Avon Valley National Park* the final Eastern Railway route through the valley* Avon Valley School...

. The route became operational in February 1966.

A lookout and picnic area were developed at the site giving tourists a view from the top of the cutting. A plaque at the lookout reads:

Windmill Hill Cutting

Deepest cutting on the standard gauge railway
and one of the deepest in Australia. The geological
nature of the site required special treatment
to consolidate the slopes. Constructed 1963-1964.

Depth (max): 34 metres

Length: 510 metres

Width: 20 – 75 metres

Height above sea level 151 metres