Sightseeing, by D.J.Enright
Along the long wide temple wall
Extends a large and detailed painting:
A demon’s head. Its mouth square open.
Inside the mouth, a room of people squatting.
Its fangs, the polished pillars of the room.
The crimson carpet on the floor, its tongue.
Inside the room, a painting on the wall:
A demon’s head. Its mouth square open.
Inside the mouth, a room of people squatting.
Their faces blank, the artist did not care.
Inside the room, a painting on the wall.
A demon’s head. Its mouth square open.
Somewhere, you are squatting. Somewhere there.
Imagination like the eyes that strain
Against the wall is happily too weak
To number all the jaws there are to slip.
I like that. 
What an interesting pome - great imagery.
The rhythm of a line in a story I read the other day suddenly made this poem pop up in my head, so I went and looked it up. It always strikes me as one to read aloud, because I think the rhythm makes the sense of the poem much stronger - I have no idea now where or when I first came across it (except that it was a long time ago!) but it has stuck in my mind for years ... anyway, glad you like it!