Greenwich

 was an area of London where the Greenwich Observatory, and the Old Royal Naval College (and before it, the Palace of Placentia) were located.

Henrietta Goodheart was an astronomer at the Observatory until 2006. (PROSE: Beautiful Chaos)

The Tenth Doctor found a spaceship trapped under Greenwich Park in 2009. (COMIC: Don't Step on the Grass)

Behind the scenes
Sophie Aldred (Ace) was born at Greenwich in 1962.

Aldred returned to Greenwich when filming Silver Nemesis. The battle against the Cybermen was filmed at the former site of the North Greenwich Gasworks, the then-future site of the O2 Arena.

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 Rani landed her TARDIS at the National Maritime Museum, whereupon Leela escaped. The Seventh Doctor, Ace, and K9 defeated the Rani's plans there.