I was thinking about this building, and it reminded me of how we’ve seen merchants traveling on land from player-controlled markets towards neutral structures, see below,
I’m not sure, specifically, how that trading mechanic will work, but it would make sense to me if this coastal market functioned in a similar way. It looks like a neutral building that the blue player is trying to control, and I’m guessing that all players can trade with it using trade ships and their own docks. If I’m correct, it seems like a really cool way to incentivize players to create multiple walled-in cities in games. If you can wall in these neutral trade locations on a map, then you simultaneously prevent your opponent from using them and guarantee yourself access. Pretty cool.
I wonder whether you can also trade by land with a coastal market, though. It would make some sense for a coastal market to trade with both ships and merchants, but I’m not sure how that would work in the game. I could see it being strange if both players traded with the same market, but by different routes. Effectively, it would be like you were trading with your enemy, which doesn’t seem realistic.
Edit: With the recent patch to AOE2, it seems like this interpretation of the neutral markets makes even more sense. As noted by another poster on an AOE2 thread,
I’ve talked about it before, but AOE4 seems to share a lot of ideas with the recent DLC additions to AOE2 (Sicilians and Delhi Sultanate both having infantry that can construct defensive buildings, Burgundians and English both having gold-generating farms, etc.). The experimentation with neutral markets in AOE2 seems like a pretty clear indicator that they are heading in that direction with AOE4, as well. Still, I’d be curious if other people have the same interpretation as me!