Southeast Asia
From Tardis Wiki, the free Doctor Who reference
Southeast Asia was home to the Great Wall of China and bordered the Pacific Ocean. (PROSE: Childhood Living)
The Ninth (PROSE: Rose) and Tenth Doctors both visited the Great Wall in South East Asia. (COMIC: The Immortal Emperor)
While in orbit around Earth, the First Doctor and Susan viewed South East Asia on the TARDIS scanner, and Susan was disappointed that she couldn't see the Great Wall from space. (PROSE: Childhood Living)
