Western Xia constructed the long wall, so-called "Chinggis Khan's wall", and fortresses on the borderline with Outer Mongolia. These remains are reported by archaeologists:The northern border of the Tangut state, XiXia: According to the archaeological evidence and written sources(Kovalev A. A.& Erdenebaatar D), http://doi.org/10.24517/00064491, Distribution and historical transition of fortresses with a side length of 130 meters on the borderline through Mongolia, HeXi corridor and LouLan: Using satellite images and GIS(Moriya K), http://doi.org/10.24517/00064490