Built in the 1850s, Sydney’s copper-domed, Italianate sandstone observatory squats atop Observatory Hill, overlooking the harbour. Inside is a collection of vintage apparatus, including Australia’s oldest working telescope (1874), as well as background on Australian astronomy and transits of Venus. Also on offer (weekends and school holidays) are child-focused tours (adult/child $10/8), including a solar telescope viewing and planetarium show. Bookings are essential for night-time stargazing sessions, which come in family-oriented (adult/child $22/17) and adult (adult/child $27/20) versions.
The observatory was originally built to determine the correct time via astronomical observations. On the roof, a signal ball still drops at exactly 1pm. The hill was also used to signal to ships from two high flagpoles, one of which has been reconstructed. Research at the observatory ceased in 1983.