Using a uniform methodology, we explored cartographic elements on almost sixty medium-scale maps showing Slovenian territory from the sixteenth to nineteenth centuries. One of the elements examined was also borders, which are very fragmented due to the great landscape diversity of Slovenia. We were interested in how borders in different periods follow the natural boundaries of the landscape and how they are cartographically represented. Lines and shapes were mostly used to display the borders. Shaded areas are more common. They are usually colored or patterned. Lines are more effective. Typically, there are different types, varying in shape, thickness, and color. Only a dozen of the maps examined lack borders. Two-thirds of the maps highlight the borders with a color.