National Brickworks began operation in 1901. Clays were dug up on site. The brickworks ceased operations in 1975, and the brickpit was subsequently used as a tip before being converted to the current Brickpit Park.
In February 1978 plans were publicly announced that the Thornleigh brickpit was to be turned into a rubbish tip. In August 1980, the kilns, office, chimney stacks and machinery shed, which had been vacant for the previous five years, were demolished. The site opened as a rubbish tip opened in 1981, transferring from Mount Colah and eventually closed on June 12, 1985. Gas burners were installed to burn off the methane gas generated by the rotting garbage and Brickpit Park was opened on the site in 2006.
