For a long time now I'd been wondering something... Is it possible to make certain features unable to be pillaged or only pillageable by certain units? See, the Sea Tunnel lets land units travel across the ocean and lakes. It's supposedly highly advanced construction and takes ages to build... And gets pillaged in a single turn by any naval unit, including Triremes. The AI adores going out to pillage these routes in each other's territory the first chance they get, and of course any barbarian units will do so as well. Later in the game, particularly on continental maps, I'll sometimes send my constructor ships to bridge a few landmasses the AI's declaring war on each other but doing nothing about it (Since despite the difference of just three to five tiles, they rarely mount up any transports and when they do it's an easily slain handful.). Bridging the gap they start shuffling their units over reliably...... Unless either side has a ship around in which case they beeline for the Tunnels on the other nation's side and pillage it immediately, which brings the war to a halt again. If they can't be made unpillageable could they be something they need to try harder to do like how pillaging a city sometimes fails to reduce its population? Or is there some weighting on how willing they are to pillage certain features that can be reduced, so they're less likely to immediately go and destroy the tunnels and render themselves unable to finish their wars? I'd probably go for a reduced weighting if that's a thing; they'd still pillage but be less likely to do so the moment a Tunnel is finished.