Augmented maps have many important applications. However, no mature registration method exists to associate unprepared maps with a Geographical Information System (GIS) database which would be used to superimpose simulation results or route display on a paper map. In this paper, we propose a method called Robust Random Dot Markers (RRDM) that can robustly track coplanar random dot patterns, which can be used to address this problem. RRDM is based on the same idea of the Random Dot Markers (RDM) proposed by [Uchiyama and Saito 2011] and it can serve as fiducial markers as well as texture independent "natural markers". We conduct a series of experiments and show that RRDM is more robust than RDM in terms of jitter, perspective distortion, under and over detection of dots in the pattern. As an example of "natural marker", we show that RRDM can successfully register unprepared printed maps only with pure geographic features, i.e. road intersections coordinates, which we retrieve from a GIS. Our method does not suffer from the drawbacks of traditional "feature-point" based registration methods which mainly based on textures, since textures may change according to different maps.