Sydney, Australia
A historic building, and imposing building. You can imagine it looking out over the port of Sydney (if you can equally imagine the absence of the Cahill Expressway). A large diorama of the Sydney area which you can walk over is on display in the foyer. The Sydney City Library occupies the building,
and sometimes has exhibitions. Free.
Listen to the audio guide for Customs House Free on WIP — starts by itself when you arrive, even with the screen off