I don’t quite understand to in my own words: to help us know what we don’t know
The answer is <u>detached</u>.
Detached means something not connected to any other structure or building, separated from the rest or isolated. In streets dead-end, at the very end of it, it's common to find some type of detached building, like a house; and such isolation don't tend to bring anything interesting or exciting to people around it, but dullness.