One thing I like about FE is the trophies you can get for defeating strong enemies (wildland bosses). However, after I have assigned them to a city, there is nothing at all that tells me I have a trophy in that city.That's a bit of a let-down.
I would like to see trophies listed in the city details view, under the list of Improvements: http://i.snag.gy/0hSc0.jpg
Also, hovering over it should show the <Description> from the abilitybonus in a small tooltip:
The heart of Morian, Ruin of Summer. Deep within his corrupted shell was a heart that still remembered verdant forests and unscarred lands. (+10% growth, +5 hit points for all units trained in this city)
This way, you get a sort of trophy rack so you can keep track of the things you've added to a city. Also it gives you a place to go back to and look at how awesome you are for doing something difficult.