When people think of Robert Frost and quote his poem “Mending Wall”  they use this in support of fence making: “Good fences make good neighbors…” but rarely  have they read the poem all the way through. Here is the heart, I believe, of this poem , at least insofar as it pertains to physical walls:

Before I built a wall I’d ask to know

What I was walling in or walling out,

And to whom I was like to give offence.

Something there is that doesn’t love a wall,

That wants it down.”

You can read the poem in its entirety, here

https://www.poetryfoundation.org/poems/44266/mending-wall