My Dad used to teach in an open-walled classroom. The kids were hard to manage, though I'm not sure the walls were the only reason :)
Regarding giving kids a sense of history (history was one of my majors so I think about this sometimes), I'm in favor of a multimedia approach to teaching history that would include viewing historical films (I have this really useful book by George MacDonald Fraser called The Hollywood History of the World that catalogs historical films for each era of history), as well as good fictional films that tie into history (stuff like the Indiana Jones movies that have historically-interesting settings--I thought that Young Indiana Jones TV series that was on for a while could've been a good educational tool for teaching the WWI era, if it was better written), field trips to historical sites, wargame simulations for teaching wars like WWII, etc. as well as textbook study. To me history is most exciting when it seems 3-dimensional (kind of like I like to study Tolkien's history through his maps because it helps me visualize the stories). Also tying it to the Bible made ancient history seem more relevant to me. Likewise tying it to modern historical events also helped get me interested in modern American history--the debate between Alexander Hamilton and Thomas Jefferson suddenly became interesting to me when I realized how it related to modern political debate. That was how I got interested in history, anyway.
The authors do excellent research, the characters are engaging, and you can skip the spicy bits, if you like! <grin> But why would you?
There's a sub-genre of historical romance that adds in real historical figures --- for example, the Roselynde series by Roberta Gellis features Eleanor of Aquitaine, Richard I (aka "The Lion-Hearted"), John (aka "of England," aka "Lackland"), and William Marshal, 4th Earl of Pembroke (aka the "Marshal of England") --- as secondary characters. Done properly, as in the Roselynde series, it is very cool stuff to read!