In this study, a combined numerical and experimental investigation of the thermal behaviour of small solar ponds with various shapes, is presented. For this purpose, two prototypes of solar ponds with square and circular cross sections and similar volumes were examined. In the small solar ponds, the side walls shading affects accumulation and storing the solar thermal energy. Therefore, for evaluating the effect of shadow shape and size on the pond performance, a model for temperature distribution in a solar pond was presented, and the thermal behaviour of the pond was investigated considering the shadow effects. Temperature changes in the storage zone were calculated numerically and compared with the experimental results. According to the results, by considering the shadow effect, the maximum temperatures of circular and square ponds were 66.8 degrees C and 65.8 degrees C, respectively. Also, the effect of the angular placement of ponds on various geographical directions has been investigated. The maximum temperature was obtained at the placement angle gamma = 0 degrees for square ponds, whereas the rectangular ponds should have been constructed at gamma = 90 degrees to achieve the maximum temperature and shadow effect reduction. The results provided a strong perspective for determining the dimensions and angular placement of the solar ponds before construction of a solar pond.