I’ve just become aware of a series of regional & city guides for Spain & SW France, called Maribel’s Guides for the Sophisticated Traveler. They’re available free online in PDF format, 16 of them, and look very interesting.
And by the way, the thumbnail for the Bilbao guide is, guess what, the Frank Gehry-designed museum which, I have no doubt, Gumbo will be visiting. See another here.