The use of decorative motifs in historical buildings has been common in all periods. These motifs were formed based on semantic concepts derived from religious sanctities. The main structure of the sanctity of mathematical numbers and geometric shapes was also derived from mystical thoughts.

The main purpose of this research is to investigate the relationship between the decorations of the tomb of Sheikh Gabriel Kalkhouran and the semantic concepts of numbers and geometry. Based on the maps of this building as well as field observations and photography of architectural decorations, the geometric and numerical semantic concepts in this work are analyzed and described; therefore, it is a qualitative research with a descriptive-analytical approach, . In this research, by examining the concepts of numbers and geometry, the relationship between the formation of decorative motifs (geometric, animal, and plant) in the building and the mystical and religious thoughts of that era was examined. The results of this research show that the geometry of the spaces forming this tomb consists of simple shapes with semantic concepts. The interior and exterior decorations of the building are also formed from these shapes and their repetition and rotation. The manifestation of mysticism is evident in the decorations with motifs and Islamic motifs, each of which is an interpretation of the world of meaning in this sacred place.