Explore the largest biosphere reserve in the rhodope mountains the red wall this paradise for orchids was included in unescos man and the biosphere program back in 1977 due to its rich biodiversity the centuries old beech tree forests of the red wall host more than 20 species of orchids including the unique ladys slipper which can be seen only in this reserve hike to one of the tallest waterfalls of the rhodope mountains slivodolsko padalo 49 m where there will be a stop for a re