Harlan Ellison wrote one classic episode of "The Outer Limits", starring Robert Culp as the "Demon with a Glass Hand", and chose the LA landmark, the Bradbury Building (no relation to Ray) as the filming site. Later used in Bladerunner, the Bradbury Building has large indoor atriums that allowed Elliso to write a chase scene in 3-D as it were - where the action went up and down, not just side-to-side.
Olite's Castle is the same: many levels, all visible from each other. Kids have a tremendous time running up and down stairs, and wavig at each other from high vantage points. So did we.
I'll let the photos speak for themselves:
In a "meta" shot, I'm shooting Yan shooting Maria:
And from there it was onward into the mountains and Basque country.