By AIDA CERKEZ-ROBINSON, Associated Press Writer Wed Sep 13, 7:56 PM ET SARAJEVO, Bosnia-Herzegovina - An Egyptologist who investigated two hills in central Bosnia believed by some to be ancient pyramids on Wednesday recommended that archaeological digs be carried out there. After investigating the two hills for a week, Dr. Mohammed Ibrahim Ali, a professor of Egyptology in Cairo, said nobody should be jumping to conclusions but having in mind everything he had seen in Visoko, his recommendations would be that "it is worth digging here." "You have to be patient. This might take decades," he said. No pyramids are known in Europe, and there are no records of any ancient civilization on the continent ever attempting to build one. However, the theory that at least two oddly shaped hills near the central Bosnian town of Visoko might be ancient pyramids covered by dirt and vegetation was proposed by an amateur researcher last year. Semir Osmanagic, who has been investigating Latin American pyramids for 15 years, organized excavations on the Visocica and Pljesivica hills, about 20 miles northwest of Sarajevo, in April. His team — made up mostly of volunteers — found that the 2,120-foot Visocica hill has 45-degree slopes pointing toward the cardinal points and a flat top. Under layers of dirt, workers discovered a paved entrance plateau, entrances to tunnels and large stone blocks. When digging at the neighboring, smaller hill of Pljesivica, the team discovered pavements on various levels of the hill. The theory has been disputed by a number of local and international experts, who claim that at no time in Bosnia's history did the region have a civilization able to build monumental structures. In June, a British archaeologist rejected claims that Visocica is a man-made structure. Professor Anthony Harding, who is president of the European Association of Archaeologists, visited the site and said the formation was natural. This did not discourage Osmanagic's team, which meanwhile excavated more pavement and stone blocks and sought help from Egypt. Ali said Osmanagic's findings raise many questions, and the answers are worth looking for. He said he could claim with certainly that the pavements on the Pljesivica hill "cannot be naturally composed." "What we are missing here are artifacts, organic material. But this kind of work should continue until facts are found," he said. However, Bosnia has little archaeological expertise. Teams of experts should be working on the hills simultaneously but the country does not even have an archaeological institute and should first establish one, he recommended. "Start now! This is the time. You are just scratching the surface. There is a lot to do here. Egypt can help you with experts," he said.