One of the takeaways of “Rikers: An Oral History,” a new book by the journalists Graham Rayman and Reuven Blau, is the shock inmates feel upon entering this run-down and lawless prison for the first time. It’s not just the sense of peril, the reek of toilets and cramped quarters, and the nullity of the concept of presumption of innocence — it’s an awareness, as one interviewee puts it, that “nobody cared and nobody was watching.”

Alongside that shock, the rapper Fat Joe tells the authors, is the awareness that, if you grew up in the projects and attended the public schools, you know this place. “I’m willing to bet that the same architect designed all three things,” he says, having visited friends at the jail complex when he was growing up. “I’m telling you I was born in Rikers.”

Rikers occupies a 415-acre island, most of it landfill, in the East River between Queens and the Bronx. If you take off from LaGuardia, there it is, right off to the left. It’s close but oddly far away. One skinny, terrifying bridge leads out to it — terrifying to prisoners, at any rate, because if your bus rolls into the river, as one detainee puts it, there’s little chance of survival when you’re in a cage and in shackles.

It’s certainly far away for relatives and other loved ones. Visiting an inmate in Rikers is a degrading experience that often takes up an entire day, between the buses and the interminable waiting, even if your visit is an hour. A lot of people give up and stop making the trip.

Rayman and Blau have each worked for The Daily News, among other New York City papers. Blau now works for The City, a nonprofit digital news site. They cast a wide net in “Rikers: An Oral History.” They’ve interviewed not just former inmates but officials, correction officers (guards hate the word “guards,” they tell us), lawyers, social workers, chaplains, gang leaders, mob guys, clinicians.

The result is a bit chaotic, as oral histories tend to be. But the chaos feels true to the experience of prison; this impressive book throws a lot at you, and much of the reading is difficult.