Here's what Trippy members say about Customs House:
"Wander around the Rocks then walk down Hicksons Road then waterfront back past Park Hyatt Sydney, Oversea Passenger Terminal (go up the multiple viewing platforms at the OPT), then along Circular Quay (stop at Customs House to look at underfloor model of Sydney), then up the lift at Circular Quay (near Wharf 2), turn left and walk along the Cahill Expressway until get into the Royal Botanic Gardens (walk past Govt House-is it open?" See More