The liquefaction-triggering potential of foundation soils is still a difficult and questionable area as the methods of determination of the liquefaction-triggering potential are only valid for free-field level sites at the present time. However, liquefaction is a major problem especially in urban areas, which have a number of structures. The nature of the problem changes dramatically at city centers, which frequently comprise close spaces and buildings with basement floors. Even though there are some recent studies in this area, further research is required. Hence, this study is focused on the liquefaction behavior of foundation soils of adjacent buildings and buildings with basement floors (i.e., floors under the ground surface). For this purpose, 3D finite-difference-based analyses were performed for generic sites using different soil, structure, and earthquake parameters. The results obtained for the structures with basements are compared with those of structures with no basement. It was shown that the presence of basements decreases the possibility of liquefaction as compared to similar structures with no basements. Similarly, analyses were performed for adjacent structures, and the corner structures in a set of adjacent structures were found to be more vulnerable to liquefaction as compared to the ones in the center.