Don't build anything in the open, only inside cities
or other sublocations. Otherwise you get one showing up
every few turns forever. Raising the civ level of the
province seems to have no effect, unless it postpones the
attacks by a few turns; savages still come by to attack
a mine in a civ 8 province, so you just need to keep
a few soldiers around. 40-50 ought to be plenty.
-- Carl Burke cburke@mitre.org