thumb|Friedrich Gerhard Rohlfs
Friedrich Gerhard Rohlfs (14 April 1831 – 2 June 1896) was a German geographer, explorer, author and adventurer.
Biography
Friedrich Gerhard Rohlfs was born at Vegesack, later part of Bremen. His father was a physician, and encouraged Rohlfs to join the field of medicine. After the ordinary course at the gymnasium of Osnabrück, he entered the Bremen corps in 1848, and took part as a volunteer in the Schleswig-Holstein campaign, being made an officer after the battle of Idstedt (July 1850). and was decorated for bravery as Chevalier of the Legion of Honour. was the first European to cross Africa from Tripoli across the Sahara desert via Lake Chad and along the Niger River and to present-day Lagos on the Gulf of Guinea from 1865 to 1867. He was the second European explorer to visit the region of the Draa River in southern Morocco. For this work he was awarded the Patron's Medal of the Royal Geographical Society of London in 1868. In 1874 Rohlfs set out from Dakhla Oasis intending to reach Kufra. By February the party was about north of Abu Ballas (Pottery Hill) in the Western Desert, looking for a way around the dunes. Accompanied by Karl Zittel and a surveyor called Jordans, Rohlfs and his colleagues experienced a torrential downpour - a rare occurrence in the desert. Rohlfs' team restocked and watered their camels and built a cairn at the place he named Regenfeld ("Rain field"). The westward progress of the expedition continued to be hampered by the north–south dune ridges of the Great Sand Sea which the loaded camels were unable to climb. The party was forced to head northwest along the easier inter-dune corridors and reached Siwa.
In 1875, he visited the United States, and lectured on his travels.