Dibella's Watch adds an entire new continent to Oblivion. It comes complete with a major city, castles, towns, villages, farms, monasteries and all the good stuff that makes up a Medieval landscape. There's also fighting to be had and quests to be made!
The village of Scarley is an idyllic little outpost in the south, supplying some good countryside vistas. Scarley is crafted to imitate the English countryside as far as possible.