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!
New land has been created in Beta 03 of the mod. More land has also been added to the north with snow and ice and high mountains. You're welcome to visit, although not much is happening there yet.