A 2 player map.
Map Name: San Francisco Red Zone
"With the advent of the Tiberium age and the evolution of Tiberium in the 2040s, the city was gradually overrun by Tiberium, becoming a hostile Red Zone. The Golden Gate Bridge survived the growth of the element and stands as a monument to the once great city."
Put the "San_Francisco" folder into this directory;
C:\Documents and Settings\ProfileName\Application Data\Command & Conquer 3 Tiberium Wars\Maps\
The folder is probably empty if you have no custom maps already.