Built in 1858, Sydney Observatory gained international recognition under Henry Chamberlain Russell, government astronomer from 1870 to 1905, who involved Sydney in the International Astrographic Catalogue, the first complete atlas of the sky. The Sydney section alone took 80 years to complete and filled 53 volumes. It became a public observatory in 1982. Night tours (booking essential) include a talk and tour, 3D Space Theatre session and viewing through a 40cm (16in) reflecting telescope. You can also explore Sydney Observatory on a self-guided day visit or daytime staff-guided telescope and 3D Space Theatre session. CityRail/ferry Circular Quay. Admission Museum & gardens free. Day tours $7; $5 reductions; $20 family. Night tours $15; $10-$12 reductions; $45 family.