Ureh
Ureh has a very high probability to be a playable town in Diablo III. A concept art piece, shown on the right, was named Ureh and there are various official concept art pieces of Ureh seen also in the image gallery.
Ureh was also a featured on a Diablo novel by Richard A. Knaak. Seen in the cover, Ureh was a central town in the story. The connection to the books is important seeing how Diablo III Lead Designer Jay Wilson commented on a recent interview: "people can expect to see characters -- from some of the books."
Ureh has also rich background - it is depicted in the book that in its history, it has worked as a gateway to hell. This has lead to speculation about Ureh's importance and place in the story.
Ureh can also be seen in the official world map.