Limpley Stoke

Limpley Stoke is a mysterious town in England, in the Real World. The reason it is so mysterious is that, wherever you go in the area around it, you will find signs informing you that there is no access to Limpley Stoke. From anywhere. Nothing goes in or out of Limpley Stoke, ever. It almost sounds like a plothole.

Investigation
Agent Morgan left on a month-long trip to investigate Limpley Stoke immediately prior to the macrovirus epidemic. It is unknown whether she did this in her capacity as a PPC Agent, or as a Time Lord. It is also unknown what she found there, except that it is apparently difficult to reach the town even by TARDIS.