So I began to look about me in the hope of finding something sufficiently interesting to keep me awake.
There was nothing in the street except the makings of a bad smell.

There was plenty of that.

I searched the opposite wall, on which the moon shone, but there was nothing there of even architectural interest.

My eyes traveled higher, and rested at last on something extremely curious.
The wall was not very high at that point.

It formed the blind rear of a house that faced into a court of some sort approached by an alley from another street.