Keri Russell, Allison Janney, and more are back in action in London, New York, and—now—Lucca, Italy.

CLIFTON PRESCOD/NETFLIX

On Location peels back the curtain on some of your favorite films, television shows, and more. This time, we ask: where was The Diplomat filmed? This story contains major spoilers for season four.

Watching The Diplomat is like being a fly on the wall in some of the world’s most powerful rooms and buildings . But the Netflix series, though often immensely dramatic, rarely puts its characters in places that reflect them intimately. Instead, as production designer Curt Beech explains, The Diplomat is about “bringing the characters together physically but never emotionally in spaces the public don’t get to see.”

“The places may be historical, but they're almost never personal,” he says. “That is what's so different about this show from a design standpoint. Usually, we're creating someone's bedroom or their house, and we dig into their family history and who they are and what they like.…