The Republic of Djibouti located in the north-eastern part of the African continent lies in the Great Rift Valley from where continents start to split. Due to the hot magma that rises from underneath, volcanoes and hot water are quite active in the valley. Travertines are calcareous rocks created where hot water gushes out. Calcium carbonates dissolved in hot water cool down and become solid when they appear on the Earth's surface. This is how travertines are formed. In the Great Rift Valley of Djibouti, there are numerous travertines, which appear as needle-like mountains.