The only survey of visitors to Olympus National Park was conducted before 2000. It showed that 100,000 people visited the park every year, 55-60 percent of them foreigners. Since then the number is believed to have increased by at least 30-35 percent. Most visitors combine a stay at the seaside in Pieria with a trip to the mountain, but only 10 percent of them know its true beauty, comments Yiannis Beinas, who has written a book and made a film about the unknown Olympus. «Most of them follow two basic routes: Litohoro-Prionia-Agapitos refuge, half of which is by car, and Litohoro-Gortia-Petrostrouga-Oropedio Mousson,» according to Beinas. Olympus, a UNESCO-designated «biosphere resource,» has hundreds of hidden treasures which cannot be highlighted due to the lack of a management plan. Within its 500-square kilometer expanse are 52 peaks ranging from 760 to 2,918 meters. Together with rocky streams and forested slopes they make an extraordinary sight, accessible by 21 hiking and climbing routes. Few people know of the Enipea, Orlia, and Kokkino Vraho waterfalls and the two seasonal lakes, Bara and Dristela. Researchers have documented 1,700 plant species on Olympus, representing 25 percent of Greek flora; 10 of those species are endemic. The mountain is also home to 32 species of mammals, 108 species of birds, a considerable number of amphibians and reptiles, and a vast but undocumented number of butterflies.