In Chap. 9 we have already dealt with visualization in special relativity. We distinguished between a more abstract representation from an outside view using Minkowski diagrams, and a representation from the first-person view. In general relativity, the prevalent focus in literature is on the abstract representation. These include, for example, the Penrose-Carter diagram for the illustration of the global structure of black-hole spacetimes, of lightlike and timelike geodesics, or of features of gravitational fields, such as quantities characterizing the curvature, or gravitational waves. In recent years, the visualization of what an observer would actually see in a four-dimensional spacetime, has received increasing attention, and this is why we shall also focus on it.