A Comet struck Earth roughly one year ago. The resulting tidal waves, storms, and earthquakes shattered civilization. We had grown too dependent upon our technology. Every society is only three meals away from revolution...
MidgardMOO is set in the remains of an affluent suburb or satellite community of a nameless west coast city (probably Seattle or Portland, but don't quote me on it). High enough in the hills to avoid tidal waves, and rural enough to make the transition to an agrarian community. Most of the inhabitants are new, many of the original land owners had left on the Day and were not able to return. The govenor is an exception. The houses are fairly spread out, and there is little useless (ex)infrastructure to get in the way. Most of the village is in the foothills of a mountain that spreads to the southwest, south and southeast. These mountains are not used by the village, but some people do live in them. A stream feeds its way down through the mountains, passing the village just to the east. This stream eventually flows into the slowly receding inland sea to the northeast. This new sea is the result of the comets impact, drowning millions of acres of land under maybe ten feet of water. Of course, there are islands out there, many with people living on them cut off for the most part from the mainland. Also, the remains of dead towns are out there, and there are rumors of whole communities living in the second stories of such towns. Fields lie to the north of the village, in the actual Valley. Beyond them, to the northwest begins the remains of the outskirts of the Old City. Many of the buildings here collapsed in the impact, and the whole place in general has gone to hell. Many people live there, digging out an abode in one place or another. A complete community lives there amoung the recage of a past age.
Beyond the overall theme of a comet impact, Midgard's theme has some finer points.
Lucifer's Hammer by Larry Niven and Jerry Pournelle
The Postman by David Brin
Folk of the Fringe by Orson Scott Card
Alas Babylon by Pat Frank
Firestorm: Songs of the Third World War by Leslie Fish (Good luck finding it! Dealer rooms at SF cons are about your only hope.)