The region and Wingecarribee River was first visited by Europeans during the late 1790s, including a 1798 expedition led by an ex-convict, John Wilson. However, John and Hamilton Hume rediscovered the area in 1814. The area was explored by Charles Throsby in 1818. Runs were taken up soon after, including by one by Charles Throsby. Harper's Mansion, which is on a hill overlooking the town, was built from 1829 to 1830. Bong Bong had been planned as a major town for the county but, as it was flood prone, the New South Wales surveyor-general Thomas Mitchell chose Berrima townsite on the road running south from Sydney to Goulburn with the intention that the town be the chief centre for southern New South Wales. The survey was conducted in 1830 and the town plan was approved in 1831. As well as its being an administrative centre, there were ambitions that the town might become a commercial and manufacturing centre, "where the wool of Argyle and Camden might be made into cloth and the hide into leather".