The site of Glenbrook, 64 kilometres west of Sydney, was just a lagoon when explorers Blaxland, Wentworth and Lawson travelled through the area on 12 May 1813 on their way across the Blue Mountains.

Ziz Zag bridges, Glenbrook (courtesy Pam Pascoe)

Lennox Bridge (completed in 1833) is located five kilometres north west of Glenbrook on Mitchell's Pass Road. The bridge was constructed by convicts under the supervision of Scottish master stone mason David Lennox. It is now Australia's second oldest stone arch bridge (the oldest on the mainland) and is listed by the National Trust.

The township developed in 1874 when it became a water-stop for steam engines on the Lapstone Zig Zag railway line. At that time it became known as Watertank. It subsequently became known as ’Wascoe Siding’ (at that time nearby Blaxland was known as Wascoe).

Pointsman's cottage, Glenbrook (courtesy Glenbrook Historical Society Collection)

The Zig Zag line was built during the 1860s by Engineer-in-Chief for the New South Wales Railways, John Whitton. The original zig zag was bypassed when a deviation was completed in 1892.

A passenger station was constructed in 1877 and the year after the name was changed to Brookdale.

Lennox Bridge, Glenbrook (courtesy Pam Pascoe)

In 1879 the site was named 'Glenbrook' by Sir John Jamieson in the belief that the creek originated from Regents Glen.

The town of Glenbrook has grown to house a population 5,055 residents (2001 Census).