How ironic that the big housing estates moving inexorably across the remaining undeveloped spaces of the Cumberland Plain have had an unexpected benefit - revealing a treasure trove of archaeological relics left by western Sydney's original inhabitants.

But that's the case, according to Paul Irish, a heritage consultant to the Historic Houses Trust.

Indigenous story ... Greg Simms has made several tools, including a shield, clubs, digging stick and woomera for the centre's Aborginal display. Credit:Wolter Peeters

''The evidence is particularly well documented around Rouse Hill,'' Irish says. ''Archaeologists, together with the local Aboriginal community, have documented a lot of evidence of that original Aboriginal occupation.

''Most of the digs took place before the houses were built, when sewer lines were being put in or roads widened. But that sort of archaeology flies under the radar because it is part of confidential planning documents.''