Timeless guidebook

Hi everyone! I am looking for recommendations for guidebooks that are "timeless". I would like to read about culture, history, customs of a destination, famous places and preferably some off the beaten track ones. My problem with guidebooks is that there is a lot of space dedicated to things like restaurants and hotels, which I am not interested in and which might change frequently.
I heard good things about Insight Guides and Rick Steves but they either don't ship to EU or custom duties are crazy.

My next planned trip is to Sicily so that's what I'm looking for right now but for the sake of future travels it would be great to gather some recommendations.