Elwin Bruno Christoffel (1829--1900) was a very able German mathematician who wrote influential work on the foundations of complex function theory, geometry and tensor theory, including the basic Riemann-Christoffel curvature tensor which became important in relativity theory. The authors take us on a tour through Christoffel's birthplace Monschau near Aachen. They reproduce pictures of a plaque at the building that replaced the house of his birth which burned down in 1835. The publication includes one certified and one probable portrait of Christoffel. The authors give the bibliography of Christoffel's 35 publications and refer to secondary literature on Christoffel's life. They do not contribute own evaluations of the work of this very original and independent thinker.