Place where Custer and his men were killed?

First of all, Custer was not ambushed at the Little Big Horn. He saw the encampment and in his arrogance he had no doubt that he would conquer the "savages". So Custer disobeyed a direct command not to engage the Indians, and attacked. He was out thought, outmanned and outmaneuvered by not only the Sioux but the cheyenne, Arapaho and a few from other tribes.