All in all Mercury is an unpleasant place to be. The planet has settlements at its poles, the only place where the temperature doesn't change too much. Since Mercury is too small to hold an atmosphere, all settlements are enclosed. The most common enterprise on Mercury is mining. In a nutshell, Mercury is for Terrans who have nowhere to turn but and don't want to be pirates.
The northern and southern ends engaged in a lengthy civil war in the late 23rd Century. As the equatorial regions of Mercury are uninhabitable desert, the war saw much aerial, mechanized, war-walker, and underground combat.
Other major cities: Hokusai
Other major cities: Beethoven, Goethe