The Department of Lands is one of the most outstanding surviving Victorian buildings in Sydney. The building has been used continuously for the purpose which it was designed for – as the administrative head office of Department of Lands. It has a long association with the public life of NSW, especially the rapid expansion of settlement during the later part of the 19th century. A vital landmark in the history of surveying, land titles and public works in New South Wales.
All distances in Australia are measure from Macquarie Place. Sometime between 1887 and 1894 the Lands Department Datum Bench Mark Plug was set into position on the front of the building and provided the origin of all levels in NSW under the Survey Co-ordination Act. In 1938, a clock for the tower and a clock system throughout the building to be driven electronically by a pendulum master clock were installed by Prouds Limited. The whole system was Australian made.
To assist surveyors in the calibration of EDM equipment, the building holds calibration baselines.