Hangzhou
From Tardis Wiki, the free Doctor Who reference
Hangzhou, (TV: The Gathering) or Han-Chow, was a city located in China, or, as Marco Polo knew it, "Cathay".
When boasting to Marco Polo about his knowledge of Cathay, the First Doctor mentioned that Han-Chow was where the finest silks were spun and woven. (PROSE: Marco Polo)