the pyramidal shape of Visočica hill. He subsequently wrote a book promoting the claim that the hill was the remains of an ancient, man-made pyramid, which he claimed was one of five colossal stone structures in the shape of a pyramid with an extensive prehistoric tunnel network. He named those structures "Bosnian pyramids", and established a charitable foundation, the 'Archaeological Park: Bosnian Pyramid of the Sun Foundation', to fund the promotion and investigation of the site. Osmanagić claimed that he wished to excavate in order to "break a cloud of negative energy, allowing the Earth to receive cosmic energy from the centre of the galaxy". In early 2006, geologists from the University of Tuzla analyzed core samples at Visočica. Their tests showed that the hill is composed of the same material as other mountains in the area: alternating layers of conglomerate, clay and sandstone. Excavations revealed layers of fractured conglomerate at Visočica, while those at Pljesevica uncovered cracked sandstone plates, separated by layers of silt and clay. Robert M. Schoch, associate professor of Natural Science at Boston University, said at the time, "What [Osmanagić has] found isn't even unusual or spectacular from the geological point of view. It's completely straightforward and mundane." In April 2006, twenty-one historians, geologists and archaeologists signed an open letter describing the excavations as amateurish and lacking proper scientific supervision. The 'Bosnian Pyramid' project is alleged to have done considerable damage to the archaeological heritage of the area, which contains ruins of a medieval capital, Roman observation post, and earlier remains. Anthony Harding, Professor of Archaeology at Exeter University and then-president of the European Association of Archeologists, said that, "Osmanagić is conducting a pseudo-archaeological project that, disgracefully, threatens to destroy parts of Bosnia's real heritage." Other claims Osmanagić's theories and credibility have come under near-universal criticism from the scientific community since he gained prominence in marketing the excavations at Visočica. He is interested in pyramids but is an amateur in their study. During this period, he has pursued graduate study at the University of Sarajevo, where his doctoral adviser was Hidajet Repovac, Professor of Sociology at Faculty of Political Science in Sarajevo. In his 2009 doctoral thesis, Osmanagić claims that the Maya civilization of Mesoamerica predates the Olmec, and that their culture mysteriously ceased to exist after the 10th century CE. He also discusses in some detail Mayan crystal skulls, positing that they were created with