Parliament Square was an area of London and the location of the Houses of Parliament.
Sherlock Holmes and John Watson passed through it, exiting down Whitehall. (PROSE: All-Consuming Fire)
By 2014, P.R.o.B.e. had relocated from a single office at Ashley House to a much larger building at Parliament Square. (HOMEVID: When to Die)
When the Daleks invaded in 2157, one of the first things they did was attack London, round up the surviving politicians at the Square, and exterminate them. (PROSE: Alien Bodies)
Behind the scenes