Built in the 1850s, Sydney’s copper-domed, Italianate sandstone observatory squats atop Observatory Hill, overlooking the harbour. Inside is an intriguing collection of vintage apparatus as well as background on Australian astronomy and transits of Venus. Fun family-focused tours (adult/child $26/22) including telescope viewing and a planetarium show are on offer at twilight daily and during the day at weekends and on school holidays. More serious stargazing is available during daily night-time sessions (adult/child $40/34). Book tours a week ahead at busy times.
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.