The protecting of ancient structures is considered a very important issue as these represents the heritage of the countries. Hence, the performance and the effect of the surroundings changes around such structures have to be understood. In this study, an investigation was performed for the problem of tilting the minaret of the AL-Khulafa mosque in Baghdad, which is tilted about 1.5 m. Detailed geophysical methods were applied to detect the tilting problems of the minaret foundation. Three tests

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... were carried out; ground penetration radar, soil electrical resistivity, crosshole seismic and triaxial tests. The results showed that the water seepage under/around the minaret due to dewatering process around the mosque have a major source for the problem. This groundwater mixed with sewage material, is found to move towards municipality pump that is located nearby the mosque fence within 35 m distance. The tests showed the apparent spread of cavities and soft zones under/around the minaret foundation. Finally, the shape and depth of foundation were able to explore from crosshole test, which is extended to a depth of 8.5 m.