Leeds

Leeds was a city in the north of England. It was located north-east of Manchester. (TV: The Lie of the Land) Dan Lewis had an apparent dislike of Leeds, and felt that Sheffield was "too close" to Leeds for his liking. (TV: The Halloween Apocalypse)

Geography
Leeds was located in northern England. (PROSE: Fear Itself) It was the location of Leeds University which was once attended by Polly Wright. (PROSE: Invasion of the Cat-People) The Odeon was a cinema in Leeds. (PROSE: Casualties of War)

20th century
From 1965, Clement McDonald spent forty years in the city, in and out of medical care. (TV: Children of Earth: Day One)

The Second Doctor once encountered a Golem in an alley in Leeds. (PROSE: Golem)

England won the Third Test of the 1981 Ashes series in Leeds against Australia. (PROSE: Graham Dilley Saves the World)

In 1999, Mark Barrington met some people from Leeds in Los Angeles. They went to the Cheesecake Factory in Marina del Ray then went to a nightclub in Hollywood. (PROSE: The King of Terror)

Colin Price came from Leeds but later moved to Hove, the home of his husband St John Colchester. (AUDIO: Future Pain)

21st century
Combat 3000 was a franchised laser tag game which had an outlet in Leeds in the 2000s. Ella went missing after playing the game, but later she returned home. (TV: Warriors of Kudlak)

In a hospital in Leeds in 2011, the Eleventh Doctor drew a Harmonelid out of a boy's ear. (COMIC: Earworm)

Leeds appeared on Mary Cooper's map of overflow camps in and around Wales. (TV: The Categories of Life)

In the 2010s, the Eleventh Doctor visited Leeds again, this time with Decky Flamboon. They found the streets of Leeds covered in snot and a giant snot monster on the loose. The Doctor shrank the monster to its original size and inserted it back up the nose of a schoolboy. (COMIC: The Runaway Bogey)

Behind the scenes
Sydney Wade and Mandip Gill were both born in Leeds.

In the real world, Leeds is located in West Yorkshire.

Dan Lewis' apparent dislike for Leeds, and nearby Sheffield, in The Halloween Apocalypse is most likely banter, stemming from the historic rivalry between Lancashire and Yorkshire. Dan is a born Liverpudlian, and the city of Liverpool was historically part of Lancashire before the reform of county boundaries in 1974; both Leeds and Sheffield are typical Yorkshire cities.