Shan Shen

From Tardis Wiki, the free Doctor Who reference

Shan Shen was a planet inhabited by humans or a near-human species with a Chinese culture. Some of its streets were filled with flags, pagodas and various crowded stalls.

The Tenth Doctor took Donna Noble to Shan Shen. She had her fortune read by a Fortune Teller working with the Trickster's Brigade.

After the Trickster's attempt to change history backfired, all of the writing on the planet - including that on the Doctor's TARDIS - changed into the phrase "Bad Wolf"; it's not known whether the writing subsequently reverted to normal. (DW: Turn Left)

It is likely that Shan Shen was a planet reserved for the Chinese, quite possibly during the Second Great and Bountiful Human Empire, when the majority of humanity left Earth to live on other planets.

Also, Donna told the fortune teller about Earth as if she hadn't heard of it. It could be that Shan Shen was so far that Donna assumed the fortune teller hadn't heard of it.