Picture of the day for September 14, 2016

Pobiti Kamani, Bulgaria. Pobiti Kamani is considered the only desert in Bulgaria and one of few found in Europe and is a natural landmark in Bulgaria since the 1930s. The desert consists of sand dunes and several groups of natural rock formations on a total area of 13 square kilometres (5.0 sq mi). The formations are mainly stone columns between 5–7 metres (16–23 ft) high and from 0.3–3 metres (0.98–9.84 ft) thick. There are a number of theories regarding the phenomenon's origin. The pioneering hypothesis can be divided roughly into two groups: suggesting an organic (coral activity) or abiotic (prismatic weathering and desertification of the rocks, formation of sand and limestone concretions, or lower Eocene bubbling reefs) origin.. Learn more.