The pillbox from episode 1 has been found. When Haldane is stood by his car and looks to the hills, we see this shot momentarily:

I asked Dr. Alexander Roniotis of Cretan Beaches about it, since his site also contains pillboxes in Crete. He asked some friends and they said it could be in the Almiros Beach area.
Richard from ReelStreets.com emailed me to say he’d found a link to the Fortifications.gr website. This in turn has a link to a Facebook group which has a lot more information (albeit in Greek). They both contain this photo and a precise location to the pillbox in question. It looks as if this is the right one!

