It is difficult to get away from circles.
Even as I type up this post, there are several objects on my table that are circles.
As a kid, I learn that a circle is a collection of points equidistant from the center.
As I get older, I understand that a circle can be regarded as an N-sided polygon, with N approaching to infinity.
Here are some examples of circles found in Inner Mongolia.
The first one is the ceiling inside a Mongolian yurt where all supporting members come together.
The other two photos show the exterior of the yurts.
So circles are everywhere!