J. Cole Hangs with San Quentin Inmates, Stays Off Death Row

J. Cole's visit with San Quentin inmates included deep conversation and plenty of photo ops -- but it did NOT include a walk down the green mile ... TMZ has learned.

Photos of Cole hanging with San Quentin prisoners surfaced this week -- showing him, and his Dreamville team, sitting and talking in the yard, cell blocks and a classroom.

While San Quentin is California's only death row prison, sources close to the institution tell us Cole only took a general civilian tour. That means he only got to see Level 1 and 2 inmates. Everyone above that level, including death row, was off limits.

We're told Cole spoke openly about some of his friends who've been incarcerated, and took an interest in San Quentin's media center ... where inmates host a podcast called "Ear Hustle."