Where was the platypus found?

The platypus is endemic to eastern and southern Australia.

The first sighting of a platypus was made on the banks of the Hawkesbury River in New South Wales in 1797, and its sighting was recorded by Lieutenant-Colonel David Collins (who later went on to establish the first colony in southern Australia). He described it in his "Account of the English Colony in New South Wales" which was published in 1802.