The Gympie Pyramid was supposedly discovered in 1975 by pseudoarchaeologist Rex Gilroy. Rex Gilroy visited several locations with ruins and odd rock formations throughout Australia. On of these such ruins near Queensland, Australia Gilroy asserts is actually a part of a pyramid built by the Egyptians or the Phoneticians. This is an extremely diffusionist view of early history. Gilroy wrote a book on this subject entitled the Pyramids of the Pacific. There are only a few of the original structures that survive, the rest, including the pyramid, now only exist in photographs. Meaning that properly trained archaeologists can not got to the site to see if the claims made by Gilroy are in fact verifiable. Furthermore, Grlroy has claimed to find Phonetician inscriptions all around Australia. The inscriptions all have deeply flawed syntax that clearly indicates the inscriptions are fakes. 
More recently a local author, Brett Green, has taken over for Gilroy in his investigation of the site. Brett Green, though more critical than Gilroy, is still not a trained archaeologist and is not critical enough to make his evidence valid. Green claims to have artifacts that suggest Asian and European occupation. Moreover, he claims that local indigenous language is similar to ancient Mediterranean and Indian languages. This is based largely on superficial, impressionistic comparisons. His complete lack of formal training in linguistics makes him entirely unfit to make these sort of comparisons. Moreover, nearby is a site called Sarina, which is said to be a phonetician port by Val Osborn. While Osborn appears to be a more scholarly source, some of her claims are still quite eccentric.
From Gilroy's assertion, others have made assertions of their own about the nature of the Gympie Pyramid. Gavin Menzies has proposed that the Gympie pyramid is evidence of Chinese explorer Zheng He discovering Australia. Menzies claims that Zheng He traveled and explored both shores of the Pacific during the late medieval times. Allegedly, there are maps whose dates, origins, and physical details prove this hypothesis. According to Mensies the Gympie Pyramid's size, height and shape are very similar to that of Ming Dynasty observation platforms used to chart locations. Gavin Mensies utilizes many flawed methods to make his assertions. In many cases, he listens to non expert advice and opinions which he has included in his research.  Menzies' use of unreliable sources like Gilroy, among others, is exactly why his research is unfounded and untrustworthy. The larger scientific community have discredited many of his most influential sources.
As of March 2016, the Gympie Pyramid site may be destroyed by the construction of the Bruce Hwy by-pass. This threat of destruction has caused the creation of a particularly interesting legal battle. The Gympie Pyramid, also known as rocky ridge was going to be bulldozed to facilitate the construction of a new highway in the area. To prevent this Kabi Kabi activist Wit-booker has made the claim that the Gympie Pyramid is associated with the local aboriginal group and its destruction would constitute cultural genocide. Wit-booker made the assertion that the artifacts that people like Gilroy, Green, and Menzies say were left by Egyptian or Chinese travelers are actually highly significant Aboriginal artifacts. The local Aboriginals are making the claim that the fact that many do not associate these artifacts with them is racist. They believe that the reason these artifacts are not already associated with them is due to the publics perception of them being to primitive to have had built the structure themselves. Another protester, Gary Tomlinson, was even arrested for trespassing and obstructing the police. He, however, claims that he is following the law while the government is not. They are claiming the authority of international law on treatment of indigenous populations. It is an interesting case as it is possible the case would not have existed if Gilroy had not brought attention to the site in the first place. This court case directly is a result of the light Gilroy shown on the site.
Many of the pseudoarchaeological ideas proposed by people like Gilroy and Menzies are based on an extreme form of diffusionism or hyperdiffusionism. Hyperdiffusionism is a concept not accepted by any real archaeologist. There is no material culture that suggests that hyperdiffusionism ever occurred. If all of the worlds culture came from one source you would expect to much similar material culture in the earliest stages of cultural development. The argument most often made is that the existence of pyramids around the world is evidence enough of a common origin, but what that argument fails to acknowledged is that the pyramid was simply the most structurally sound shape to build tall monuments before the age of steal. With only stone to build, a pyramid would be the most stable way to build a tall and imposing structure.  Furthermore, hyperdiffusionalism is often linked to more outlandish concepts like Atlantis. This so called lost continent is often the location which culture is said to have had disseminated out of as well as the idea of pyramid construction. In contrast, sometimes aliens are given the credit for hyperdiffusion, only it is their culture being spread rather than a human originated culture. 
The notion of the Gympie Pyramid was also tied to the concept of "Pyramidiots". Gilroy suggest that the Egyptians may have been the culture to build the Gympie Pyramid. For this to be true, the Egyptians must have been more advanced them modern day archaeologists give them credit for. For Egyptians to have nvigated to Australia and back they would have to have had an extremely developed sense of navigation and much more ocean worth boats then we see in the archaeoloical record. This over estimation of Egyptian capabilities is nothing new. Pyramidiots believe in the superiority of Egyptian wisdom. This over estimation is especially in terms of their math skills has been present since the west gained intrest in the Nile. But, despite Flinders Petrie proving in the 1880's that this was not the case, the idea has perpetuated. 
Rex Gilroy has been disproven and thoroughly discredited by academic research over the last twenty years or so. 
The so called Gympie Pyramid is likely instead the remains of a 19th century vineyard terracing.
- Newbrook, Mark. "Zheng He in the Americas and Other Unlikely Tales of Exploration and Discovery." Skeptical Inquirer (2016).
- Richardson, W. A. R. "Gavin Menzies' cartographic fiction: the case of the Chinese'discovery'of Australia." Globe, The 56 (2004): 1.
- Gorrie, Arthur"native title claim over gympie pyramid Rocky Ridge land claim; International law cited as basis for claim to block Bruce Hwy by-pass." Gympie Times [Gympie, Australia], 15 Mar. 2016. Infotrac Newsstand Accessed 1 Dec. 2017.
- de Montellano, Bernard Ortiz, Gabriel Haslip-Viera, and Warren Barbour. "They were not here before Columbus: Afrocentric Hyperdiffusionism in the 1990s." Ethnohistory (1997): 199-234.
- Normark, Johan. "Blogging about the End Times: Dealing with the Fringes of Archaeology." AP: Online Journal in Public Archaeology 5 (2015): 67-96.
- BIANCHI, ROBERT STEVEN. “Forum: Pyramidiots.” Archaeology, vol. 44, no. 6, 1991, pp. 84–84. JSTOR.
Green, Brett. Gympie Pyramid. 2004, The Dhanurian Society. Accessed 30 Nov. 2017.