Zero Obelisk is a heritage-listed survey marker on the east bank of the Warrego River, Barringun, Shire of Paroo, Queensland, Australia.

The survey work began at Zero Obelisk at Barringun, the division of work between the surveyors being described by Cameron in a letter to his uncle, Ewen Cameron:[1]Mr Watson is responsible for chainage while I am for the astronomical portion in finding true meridian, giving true bearing, setting off the chords, and finding latitude at every convenient site.After observations at Barringun to determine the latitude, the team began surveying the border in a westerly direction to the intersection with the border with South Australia at Longitude 141° E, known as Cameron Corner.

This section of the survey took 12 months and 15 days to complete and details of it were given in the first Annual Report of the NSW Department of Lands 1880 Appendix 1.

It illustrates a remarkable feat of surveying in the nineteenth century and is a reminder of the extraordinarily difficult conditions under which many early surveyors worked.

The Zero Obelisk is one of the few extant physical reminders of the official survey undertaking to mark the Queensland - New South Wales border.

[1] The place has a special association with the life or work of a particular person, group or organisation of importance in Queensland's history.

As a commemoration of one of his most notable accomplishments, the obelisk has an important association with the life and career of JB Cameron and other surveyors, whose work contributed to the development of Australia.