Klee on street corners

Walking through the streets, sometimes some traces in the landscape caught my attention.
Especially a triangle that remains on the wall is interesting. It's lost the roof, and now it looks like an abstract painting.
Although it doesn't actually look like Klee's works at all, I'm reminded of them.

This is a comparatively realistic mountain whose background looks like clouds drawn with an airbrush.

This work has a high degree of abstraction. The arrangement of the elements is cool, such as the straight lines carved sharply on the wall surface, curving lines of piping and the small circle of the ventilation.
T.S