Unique City Improvment for each Civ

[Goober]

I am wondering what you guys would think of having a Unique City Improvment for each Civ? Kinda like the UU, this could be only build by the Civ, and would give some kinda bonus.

Or, Alternatively, this could be built by all Civs, but then that would make a LOT of improvments . . .

Anyway, just thought of this idea, and was wondering what you guys and gals think (It would make choosing a Civ all that much harder)

Ohh, also, if you could give suggestions as to possible City Improvments for each Civ. Ex: A Tim Hortons Donut Shop for a theoretical Canadian Civ.