Season 2, Episode 27.
Original air date: 1 April 1957.
Robin and Little John head for the coast, to help their friend Joseph of Cordoba in his secret plan to bring a shipload of jewish refugees, escaping persecution in their own country, to the the seaside town of York.
Cast: Richard Greene (Robin Hood), Archie Duncan (Little John), Alan Wheatley (Sheriff of Nottingham), Helena de Crespo (Esther), Karel Stepanek (Joseph of Cordoba), Allan Cuthbertson (Malbete), Emrys Leyshon (Alfred), Paul Eddington (Aaron), Wilfrid Brambell (Fisherman), Desmond Roberts (Large Man) and Edmond Warwick (Drinker).
From IMDB.

The characters in this episode are travelling to the port town of Grimsby from York, which is about 50 miles inland.

The 66 in the title refers to this being episode #66 of the series. It is episode 27 of season 2, and season one had 39 episodes.

What does the 66 mean? If it is for the year the show aired it should be more closely to 1956.

Glad to see that he/she uploaded this. An interesting episode to say the least. A Plea for tolerance to a large extent. The script is perhaps a bit too sugar-coated for some tastes, but it's good old TV fun nevertheless.