Pisa with several layers of different materials, various kinds of soft soil deposits and the powder of soft clay and very deep, but in the form of a meter place is the underground water.

• 比萨斜塔下的有好几层不同材质的土层，各种软质粉土的沉淀物和非常软的粘土相间形成，而在深约一米的地方则是地下水层。