When describing how he prepared for playing the role of young Indiana Jones, River Phoenix explained that he didn't really base his portrayal on the Indiana Jones character.  Instead, he decided to do his rendition of actor Harrison Ford. So he observed Ford out of character before acting his part.

While filming in Petra, Jordan, the Jordanian Royal Family (Queen Noor, Prince Hamzah, Prince Hashim and Princess Iman) visited the set.

The temple right at the end of the movie exists, but not in Alexandretta. It is in Petra, in Jordan. However, there is no inside to it - the doorway that can be seen on screen leads to a very small room - about ten foot by ten foot. Similarly, they would be unable to get "lost" down the valley as the valley stretches for about a mile or so, and there is no other route but out.

River Phoenix, who plays Harrison Ford's younger self in this film, also played his son in The Mosquito Coast.

The film stars a former James Bond (Sean Connery), a former Bond ally (John Rhys-Davies), a former Bond girl (Alison Doody), two former Bond commanding officers ('Byrne, Michael' and Billy J. Mitchell), a former Bond nightclub owner (Vernon Dobtcheff), and three former Bond villains (Julian Glover, Stefan Kalipha and Pat Roach).  So that's 9 James Bond stars in all.  Sort of reflects on Spielberg's dream to direct a James Bond movie.

Begins with a shot of a rock in Utah which is reminiscent of the Paramount Pictures logo. (See also Raiders of the Lost Ark, and Indiana Jones and the Temple of Doom)

Walter Donovan was played by Julian Glover, and Donovan's wife was played by Glover's wife, Isla Blair.

The second film in which 'Byrne, Michael' portrays a Nazi opposite Harrison Ford. The first was Force 10 from Navarone.

Actor Pat Roach appears as a thug in all three Indiana Jones movies. He's both the Giant Sherpa and a mechanic in Raiders of the Lost Ark, he's the Chief Guard (who gets crushed by the rock crusher) in Indiana Jones and the Temple of Doom, and he's a Gestapo officer in Last Crusade.  His roll in Last Crusade was very short, but in fact most of his scene was cut.

Michael Sheard, who appears uncredited in Last Crusade as Hitler, was Admiral Ozzel in The Empire Strikes Back.

Julian Glover, who appears as Walter Donovan, played General Veers in The Empire Strikes Back.

Michael Sheard has also played the role of Adolf Hitler in: The Dirty Dozen: The Next Mission, Rogue Male, and The Tomorrow People.

Actor Michael Sheard, who appears uncredited as Hitler, has at various times in his career played Hitler, Heinrich Himmler, and Hermann Goering, all three of the top Nazis.

John Williams inserts the Ark of the Covenant's theme from Raiders of the Lost Ark when Indy and Elsa come across a representation of it on a wall in the catacombs below Venice, a cleaver reference to Raiders.

The character named "Fedora" (played by Richard Young) in the credits was, in the script, originally named Abner Ravenwood, Marion Ravenwood's father and Indiana's mentor who is spoke of in Raiders of the Lost Ark.

Director Steven Spielberg included the opening sequence with Indy as a Scout as a tribute to his own experiences as a Boy Scout.

Last Crusade shows us the origin of Indy's fear of snakes in Raiders of the Lost Ark.

Harrison Ford cut his chin in a car accident in Northern California when he was about 20. In the movie, this cut is explained by young Indiana Jones cutting his chin with a whip.

When making Star Wars, George Lucas owned a dog named "Indiana" who was the inspiration for Chewbacca and is where the name for Indy came from.

The dog barking when young Indy passes with the cross in his hand is an Alaskan malamute, the same type of dog the Lucases owned in the late 1970s (as mentioned above).

Although Sean Connery is only 12 years older than Harrison Ford, he plays his father.  Though considering this is Sean Connery we're talking about, that almost seems plausable.

The deleted scene featuring Suzanne Roquette as the "Film Director" during the Nazi rally was intended as a reference to filmmaker Leni Riefenstahl and her propaganda documentary, Triumph of the Will. Both Steven Spielberg and George Lucas have often quoted her films.

The march heard at the Nazi rally during the book burning scene in Berlin is "Der Koniggratzer" by Gottfried Piefke.

In the movie the grail is located in the Republic of Hatay near the city of Alexandretta. There actually was a Republic of Hatay from 1938 to 1939, after the region was granted independence from French Syria and before it became a province of Turkey. The capital of Hatay was Alexandretta before 1939 when the city's name was changed to Iskenderun and the capital moved to Antioch.

Chris Columbus wrote a rejected drafted in which Indy traveled to Africa and dueled a Monkey prince, but the script was also rejected because of too many negative African stereotypes

Just after watching Indiana wrestling with a Nazi, the soldier who looked through the periscope says something to his teammates in German. What he says translates as, "The American, he fights like a girl."

Indy's trademark hat, jacket and whip currently reside in the American History Museum. It is unknown whether, if a sequel is made, the museum will return the hat and whip.

According to the address on the package he received from Italy, during Last Crusade, Indy teaches at "Barnett College".

Actor Michael Sheard, appearing uncredited as Hitler, also appeared in Raiders of the Lost Ark, again uncredited, as the U-Boat Captain.

Having Sean Connery play Jones' father was an inside joke to James Bond being the father of Indiana Jones. Spielberg had always wanted to do a Bond film but did Indiana Jones as a James Bond type character.

Indiana Jones' horse also appeared in Rambo III as John Rambo's horse.

When making Star Wars, George Lucas owned a dog named "Indiana". This means that Sallah's laughing "you were named after a dog?" is true.

In the original theatrical trailer for Last Crusade, Ford is shown stapling his hat to his head witha staple gun after having it fly off several times.  This was actually done as a joke, but here are some photographs so you can see what we are talking about: