Þingvellir is another site in Iceland. I agree that they should have several more. Also interesting that they would choose a location that people aren't allowed to visit (except a few scientists).
I think it is either the episode with the headhunters, the one where that rocket goes off course and lands on Gary's island, or the one with the hilarious Japanese guy who doesn't know that WWII is over. In any case, he's not getting off the island anytime soon.