SENOIA, Ga. — A drive through the 120 acres of sound stages and Georgia countryside that serve as home base of AMC’s “The Walking Dead” encompasses landmarks both grandiose, like the ersatz colonial mansion built for the Hilltop set, and quietly chilling, like the shady grove where the arch-villain Negan bludgeoned two of the show’s most beloved characters to death last fall.

But perhaps the most striking site is the simple screening theater where the actors do script read-throughs, particularly the wall containing headshots of the 43 cast members killed off during the zombie apocalypse drama’s seven seasons. Soon your eye drifts away from the victims toward the negative space surrounding their doomed faces: There’s plenty of wall left to fill.

“The Walking Dead” resumes doing so on Sunday, Oct. 22, when it kicks off Season 8 with the 100th episode of its run. It is a notable TV milestone for such a physically intense, tightly serialized narrative; typically, it is formulaic sitcoms and procedurals that achieve such longevity.

Based on the long-running comic book by Robert Kirkman, who is also an executive producer for the series, “The Walking Dead” remains a tremendous hit. It has been the most-watched series among younger viewers for five consecutive years and is the hub of a lucrative franchise that has spun off additional shows, like “Fear the Walking Dead,” and other brand extensions.