Greenwich was an area of London in which the Royal Observatory was located. (PROSE: The Curious Case of the Miniature Menaces) Henrietta Goodheart was an astronomer at the observatory until 2006. (PROSE: Beautiful Chaos)
Greenwich was located on the south side of the River Thames. Across the Thames to the north-west was Tower Hamlets, north was Newham and north-east was Barking. Greenwich shared its eastern border with Bexley, its southern border with Bromley and its western border with Lewisham. (TV: Revenge of the Slitheen)
In 1833, the Eighth Doctor and Josie Day sailed through Greenwich on a boat. In order to send an Omsonii home, Josie had to tell the Doctor the exact time on the Greenwich Naval College clock. (COMIC: The Time Ball)
In 1894, the Paternoster Gang discovered an infestation of Gremlins in the Royal Observatory. They stopped the Gremlins from destroying the observatory and helped them find a new home at the bottom of the River Thames. (PROSE: The Curious Case of the Miniature Menaces)
In the 2210s, Susan visited the airspace command centre in Greenwich after being led there in a ploy by the Eighth Doctor to draw her attention away from a Time Lord tesseract calling her up to the Last Great Time War. (AUDIO: All Hands on Deck)
In an alternate 2006, Barbara Wright could see Greenwich when looking south from atop the Canary Wharf Tower. In this timeline, the hospital had been destroyed, however the Royal Observatory remained unscathed. (PROSE: The Time Travellers)
Behind the scenes
Much of Dimensions in Time took place in Greenwich. The Seventh Doctor and Ace landed his TARDIS next to the Cutty Sark in November 1973. Also that year, Mike Yates drove the Third Doctor to meet Brigadier Lethbridge-Stewart's helicopter at the Old Royal Naval College's Grand Square on the Thames; after a quick hop to the college's Painted Hall, the Doctor emerged as the Sixth Doctor, the only time seen in this incarnation with Lethbridge-Stewart. In November of either 1973, 1993, or 2013, the First Rani landed her TARDIS at the National Maritime Museum, whereupon Leela escaped. The Seventh Doctor, Ace, and K9 defeated the Rani's plans there.
- Yates had not yet been cashiered in Invasion of the Dinosaurs; the Doctor was trying to get to the TARDIS which he (in his seventh incarnation) parked in 1973.