Those are photos of the
Devil's Tower, the first National Monument created by Congress.
It is located in the north east corner of Wyoming, in Crook County. Sort of northeast of Moorcroft and northwest of Sundance, Wyoming. I went to the tower every summer when growing up in Campbell County for the "Old Settler's Picnic". The only day of the year no entry charge was required to get into the sight. You can walk around it, which was a summer ritual for all of us kids. Now Casper College uses it for it's mountain climbing courses.
Hope this helps.