Mono Monday - Squares

Wandering around town this afternoon I came across these floor tiles in Westminster Arcade and their square shape reminded me of something I read a few weeks ago about square poems.
As this week's Mono Monday theme is poem related I thought this would fit the bill for a blip.
A square poem is one where the number of words per line equals the number of lines, and, if the poem is read vertically, (first word of first line, then second word of second line and so on...) it yields the same poem.

Being of an engineering background (and slightly OCD I am told!) such things intrigue me.

The best known and often cited example is the poem by Lewis Carrol:

I often wondered when I cursed,
Often feared where I would be—
Wondered where she'd yield her love,
 When I yield, so will she.
I would her will be pitied!
Cursed be love! She pitied me..

There are some more examples here.