Now a suburb of Sydney, Castlereagh is one of Australia's most historic sites, being one of Governor Lachlan Macquarie's five towns founded in 1810.

After two hundred years, the rich river flats continue to provide for a thriving agricultural industry along the Nepean River. Many of this district's pioneering families originated from Castlereagh. The suburb's historical importance is reflected in its many surviving farmhouses, outbuildings, churches and cemeteries. Castlereagh Road is an important transport link connecting the Hawkesbury and Penrith regions. The impact of the massive Penrith Lakes Scheme has changed the face of Castlereagh and its neighbouring suburbs.


Brief history: This suburb takes its name from the Irish peer, Lord Viscount Castlereagh (1769-1822), who was responsible for the Act of Union between Ireland and England in 1803. Governor Lachlan Macquarie named the area in December 1810 during a tour of the Hawkesbury-Nepean region not long after his arrival in the Colony of New South Wales. Macquarie chose Castlereagh as one of his five towns, the others being Windsor, Richmond, Wilberforce, and Pitt Town.