(written from a Production point of view)
The European Town was a backlot on the Paramount Pictures lot before the studio fire on 25 August 1983, which resulted in the destruction of most standing outdoor sets, and later the revamp of the studio facilities.
This backlot was used as a filming location for the Star Trek: The Original Series episodes "Patterns of Force" and "All Our Yesterdays". For the former, the backlot depicted the surface of Ekos. Filming took place on Wednesday 29 November 1967. For the latter, it served as the location for the scenes set in Sarpeidon's medievalesque-era past. Filming took place on Friday 20 December 1968.