In the last few decades we not only witnessed dilapidation but also a dirtying of surfaces belonging to monuments, and this applies to Croatia as well as abroad. Despite the frequent opinion expressed by laymen, this is neither a sudden nor an accelerated process of deterioration. The fact remains that over the past several decades a lot of attention began to be focused on monuments as historical assets that need to be preserved, thus invariably touching on their state of preservation. Wishing to document the degree of deterioration and dirtying of the monuments at Pula, Croatia, we embarked on a tour. We began with monuments from the Roman period, i.e., with the Double Gate to be precise. Our goal is to set up a data base consisting of written reports, graphical tables showing degradation, and photo documentation showing the entire range of degradation processes that we observed. With this article we want to expose and explain the goals of these endeavors in a simplified, summarized form, providing on the way the solutions needed for the preservation of these monuments. Publication Abstract