Two inland sea maps this week, both with mining/mysticism leaders (this and Silverbow's game). Great wall is something I'd not really considered on this map type before because I always thought the map edges would be good defence. But ... I've tried for it in both cases because of the starting techs and several forests ..... and been very pleased with the decision both times. I think it's because although you have the map edges, you never have a cosy corner and barbs WILL be an issue.
Edit: Hope it's not too much of a spoiler that a mining/mysticism leader can chop the great wall and be reasonably sure to get it
Edit: Hope it's not too much of a spoiler that a mining/mysticism leader can chop the great wall and be reasonably sure to get it
