After training as a missionary in Basel, Johannes Rebmann worked in East Africa (today's Kenya and Tanzania) for an English missionary society from 1845 to 1875. On 11 May 1848 he became the first white man to see the snow-covered peak of Mount Kilimanjaro. His 1848/49 diary is held at the local town archive. In the autumn of 1848 Rebmann produced the first map of the area around Mount Kilimanjaro, together with the missionaries Jakob Erhard from Bönnigheim and Dr. Ludwig Krapf from Derendigen.
The Johannes Rebmann House features a missionary room, dedicated to the memory of all of the men and women from Gerlingen who went as missionaries to Africa, India and China in the 19th and 20th century.