In his review of GURPS Action Adventure 1: Templars' Gold, Mailanka introduces the charming phrase "action documentaries" to describe adventures which also contain interesting educational content. You play a fun adventure, but you also learn stuff you didn't know before. And that's a marvelous idea, particularly for a game as frequently entangled in history and real world concerns as GURPS.
So naturally I started thinking about how one would write such a thing. To start with, it's probably best to attach such an adventure to some existing product line. For the 20th and early 21st century, that's clearly the Action line. While I wouldn't write it, there's room for such things around more obscure corners of WWI (the war in Africa, for example), some of the less European, more Asian parts of the Russian Revolution, events around the end of the Qing dynasty, the settlement of WWII (The Third Man or intrigue around landing Trieste as part of Italy as an adventure, for example), never-ending fun and games around Kashmir, decolonization struggles in Africa, and on and on and on.
But I'm not the guy to write those. My interests run somewhat deeper back in time, which is a bit problematic. There's GURPS Historical Adventures line to tag things with. There are, though, hot spots, and GURPS Renaissance Venice: Spies of Venice points the way to how fact-heavy adventures might be labeled. For example, I can imagine GURPS Renaissance Florence: Pazzi in the Palace set around the Pazzi conspiracy and the activities of Medici allies at the time. The adventure would be part location, providing detailed plans and descriptions of the Palazzo Vecchio, and part adventure, challenging adventurers to carefully maneuver Pazzi supporters into a couple of rooms so that they can be locked in and held before word gets out that the attempt to assassinate Lorenzo has failed and they run for the hills. It's more focused than a full Hot Spot, and has the reusable content of a Location (into which category such an adventure would nearly fall), but it's also got something quite concrete to do. I've already got commitments and prospects stretching into the New Year so that's not the kind of thing I'm likely to take up soon, but it bears thinking about.