In Asia, the barbed wire strands that Americans are used to at the tops of walls are replaced by shards of glass. This over the top example is apparently from Vietnam, a photo taken in 2010. Many compound walls will have at least a line of shards down the center of the wall caps.
My Dad, Mom and I lived in two houses in Dacca, then East Pakistan, now Bangladesh. This was August, 1967 - June, 1969. Both house compound walls had a centerline of glass shards. The compound iron gates locked. There was a gate guard on staff. Everyone had a staff. Ours (a Western family of three) was a butler, a cook and a gate guard. The school my Dad superintended had a driver. He was ours too. You had to hire a service staff or else risk consequences. That was what we were told. Anyone, local or foreign above a certain economic level had servants.
I worked hard at it,
at erasing the scuff marks
in the ivy trails
on the outer wall.
A lookout told me you stood
on the glass shard top
face, the concreted
cap of that high wall and hailed
me but I was not
at home, not at all.
I guess that’s just the right thing.
I hope you got down
okay. As for me,
the trip went as it should have
and I made a pile.
Some years ago my poetry took on a mythic flavor and I became a character in my own poems, a mage, "the man of the Northern Wall". This apellation is not completely fictional. My middle name is Noordwal, a Dutch term for north wall, though in current Dutch it mainly means north bank as in riverbank. I was told that an ancestor, a Portugese Jew escaping the Inquisition, settled in a small Dutch town and took this name from where he settled, near the north wall of the town. I have thought for a long time that -wal meant wall, think my mother told me that. A linguist might say that my usage is no longer common, is an older usage, but then the Inquisition happened in Portugal a few centuries ago, right around the time the Moors lost control of the Iberian Peninsula and the Jews lost the modest protection given them by Islam. Now I write as this mage, my poetry persona.