The Indian Watchtower sits on a promontory at the Eastern end of the South Rim. From this vantage point, you get about a 270-degree view.
The tower was designed by architect Mary Colter in 1930. An artist in the mold of Frederick Law Olmstead, she really knew what she was doing when it came to harmonizing a structure with its surroundings.
As impressive as the watchtower is on the outside, it's the interior, here, that was a delightful surprise to me.