Baltimore

 was an American city, situated in the state of Maryland, proximate to both Bethesda and Washington, DC. (PDA: Blue Box) It was Peri Brown's home town, and once the location of a Cyberman invasion that was thwarted by the sixth Doctor. (BFA: The Reaping) It was also Edgar Allan Poe's home town, and the first Doctor, Ian and Barbara once encountered Poe there, near the end of his life. (ST: The True and Indisputable Facts in the Matter of the Ram's Skull)

The Institute of Space Studies, a research organisation which UNIT consulted on extraterrestrial phenomena, was headquartered there. (DW: Spearhead from Space)

Some of its known inhabitants, aside from Peri, were Janine Foster, her mother; Anthony, Kathy and Nate Chambers; Daniel Woods, Lt Doyle, Mrs van Gysegham and Natalie Hamilton.