Hong Kong

Hong Kong was a city on Earth. The Thirteenth Doctor described it as the Gateway between East and West. (COMIC: The White Dragon)

Geography
Hong Kong was by the coast, and had a significant harbour. Off one section of the coast was Aberdeen, the floating village, and across the sea from Hong Kong was Guangli Bay. Within Hong Kong was the Walled City of Kowloon. At one point it was a slum, but by the mid-1970s it was one of the more upmarket neighbourhoods with over twenty thousand people living there. (COMIC: The White Dragon, PROSE: Exclave)

19th century
In the 1820s, the samurai Casper Knox met with the chief superintendent of trade in Hong Kong in negotiating a deal between the British and his lord Takagi Mamoru, who would send a cargo of modern weapons to Edo as a gift to the Emperor Tokugawa Ienari on behalf of the superintendent. (AUDIO: The Barbarians and the Samurai)

20th century
At some point prior to 1972, Britain took control of Hong Kong. (COMIC: The White Dragon) The Unbound Doctor recalled having been present when the Union Jack was raised and the tears that the natives shed at the sight. (AUDIO: Sympathy for the Devil)

In 1940, Chen Luo killed his friend Hai Lan whilst fishing in Guangli Bay in order to get his hands on the Kalatra egg. Sometime later, the egg hatched, and Chen named the creature Shui Long, or "White Dragon". Chen Luo used Shui Long to get rid of his competition, and became a feared Crime Lord. (COMIC: The White Dragon)

In 1972, the Thirteenth Doctor, Yasmin Khan, Ryan Sinclair and Graham O'Brien, with the help of Bruce Lee, stopped Shui Long and the Kalatra taking control of Earth. (COMIC: The White Dragon)

In December 1974, the Sixth Doctor and Peri Brown saved a monk named Hu Cheung from a Triad gang in the city. (PROSE: Exclave)

In 1979, Tegan Jovanka went on holiday to Hong Kong. (PROSE: Cold Fusion)

Brigadier Lethbridge-Stewart met the Eighth Doctor in Hong Kong in 1988 where they encountered the Embodiment of Gris. (PROSE: The Dying Days)

In December that year, Hong Kong was one of the stops made by the Neptune on its around-the-world journey. (PROSE: Dateline to Deadline)

Britain was to hand Hong Kong back to China in 1997. The Ice Warriors took over the UK that year and China wouldn't oppose them diplomatically for fear the new government wouldn't hand the city back. (PROSE: The Dying Days)

Sarah Jane Smith assisted the Seventh Doctor in 1997 whilst investigating the Cortez Project in Hong Kong. (PROSE: Bullet Time)

21st century
In the 2020s, a missing British astronaut Adam Lang was found in Hong Kong by his husband Jake Willis, Graham O'Brien and Yasmin Khan. (TV: Praxeus)

In 2021, Iris Wildthyme and Panda visited Hong Kong. (PROSE: The Shape of Things)

In 2048, China was taken over by Hong Kong. (PROSE: St Anthony's Fire)

Parallel universes
In the Unbound Universe, a disgraced Brigadier Lethbridge-Stewart moved to Hong Kong. On 30 June 1997, when the city was due to be turned over to China, the Master fled to the city, allegedly to defect back to the British but actually sought to take over the Ke Le Divisions and China. Having recently crashed in Hong Kong, the Doctor struck a deal with the Master, agreeing to give him a lift aboard his TARDIS if he let the UNIT force evacuate before the Handover.

When the group reached the waterfront, the Master betrayed them. Anticipating this, the Doctor duped the Master into The Little England pub while he and Lethbridge-Stewart took off in the TARDIS to dispose of the last mental parasite in Mongolia. Having discovered he'd been duped in time to watch the TARDIS take off, the Master tried to get a ride from Colonel Wood only for the parasites to be destroyed, causing the Ke Le Divisions, having been waiting for the Master, to go insane and open fire on the crowds as they celebrated the Handover. (AUDIO: Sympathy for the Devil) By one account, the Doctor and Lethbridge-Stewart eventually returned to the city for a peaceful retirement, helping the Sixth Doctor and Evelyn Smythe when they had crossed universes. (AUDIO: The 100 Days of the Doctor)

On E364449, Pik Lim was ejected from the Convent of Infinite Vacancy in Hong Kong. (PROSE: All the Fun of the Fear)

Other references
Some resurrected humans compared the City of the Saved to Hong Kong. (PROSE: Of the City of the Saved...)

Behind the scenes

 * Complete film telerecordings of all four episodes of The Tomb of the Cybermen were found in Hong Kong TV station RTV/ATV and returned to the BBC in late 1991.
 * The last Governor of Hong Kong was Chris Patten. In Sympathy for the Devil, it's Brian Hook: an old lecturer of Jonathan Clements, who "was annoyed that he didn't get to be the last governor".