Whether by choice, by laziness on the part of those on research duty, or by good old fashioned mistakes, film history is rife with historical anachronisms. Here are 15 of the most glaring and/or just plain interesting. (Go home, llamas, you’re on the wrong continent.)

1. BACK TO THE FUTURE (1985)

It feels a bit weird to point out an anachronism in a movie about time travel. Nevertheless, Back to the Future’s Marty McFly, stuck in 1955, probably didn’t fix the DeLorean and hop forward to 1958 so he could pick up a Gibson ES-345 guitar (introduced that year) to use for his rockin’ rendition of “Johnny B. Goode” at Hill Valley High’s Enchantment Under the Sea dance. Probably.

2. THE HURT LOCKER (2009)

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Early on in Kathryn Bigelow’s Oscar-winning war drama The Hurt Locker, Specialist Owen Eldridge (Brian Geraghty) comments that a local man filming him is “getting ready to put me on YouTube.” Not unless that man is a time traveler: The Hurt Locker is set in 2004, and YouTube didn’t get its start until 2005. That’s not the movie’s only technological inaccuracy: an iPod Touch makes an appearance despite not being introduced until 2007, and Eldridge is seen playing Gears of War (released in 2006) on an Xbox 360 (released in 2005).

3. RAIDERS OF THE LOST ARK (1981)

A map illustrating Indiana Jones’ travels in Raiders of the Lost Ark sees the intrepid archaeologist/explorer passing near Thailand on his way to Nepal—a bit odd, considering Raiders is set in 1936, and Thailand was called “Siam” until 1939.

4. THE AVIATOR (2004)

Though it’s weird to think of a time before chocolate chip cookies, they were in fact invented by Ruth Graves Wakefield in the 1930s. Which means that Howard Hughes—who ordered “10 chocolate chip cookies, medium chips, not too close to the outside” in a scene from The Aviator, which is set in 1928—will have to wait a while

5. THE GODFATHER (1972)

Per Francis Ford Coppola on DVD commentary for The Godfather, it was insufficient attention paid during second unit shots that allowed this late 1940s/early 1950s crime drama to suffer an accidental invasion of the hippies. In a scene where Michael Corleone goes to Vegas, you can see a few distinctly out of place men hanging out in the background.

6. FORREST GUMP (1994)

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Forrest Gump’s galumphing through 20th-century history took him to the Vietnam War, into President Kennedy’s White House, and into the orbit of Apple. Lieutenant Dan invested Gump’s shrimping money into the future tech behemoth, which would make Gump a millionaire if he still had the stock today. (And if he were, you know, real.) Except it looks like Lieutenant Dan got swindled; the letter Gump received from Apple thanking him for his investment is dated 1975, but Apple didn’t go public until 1980.

7. SUPER 8 (2011)

Had Rubik’s Cubes been introduced to U.S. shores back in 1979, when J.J. Abrams’ Super 8 was set? No. No they had not. A Sony Walkman put in an appearance in that same movie, and they were available domestically at the time, but they were so new that a gas station attendant out in Ohio probably wouldn’t have owned one.

8. BRAVEHEART (1995)

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Though it’s one of the best known movies about Scottish history, Braveheart director/star Mel Gibson probably should have ditched Scotland’s most iconic piece of clothing, the kilt. (In favor of some other lower-body covering, obviously—Braveheart is R-rated, but it’s not that R-rated.) The modern-day kilt, according to Hugh Trevor-Roper’s The Highland Tradition of Scotland, “is unknown before the 18th century… [F]ar from being a traditional Highland dress, it was invented by an Englishman after the Union of 1707; and the differentiated ‘clan tartans’ are an even later invention.” Needless to say, 13th-century freedom fighter William Wallace would not have been wearing one.

9. THE UNTOUCHABLES (1987)

The Canadian flag design painted on the side of some wooden crates in Brian De Palma’s The Untouchables has only been in use since 1965. Before then—say, in the ‘30s, when The Untouchables was set—the flag was a mash-up of the Coat of Arms of Canada and the Union Jack.

10. GLADIATOR (2000)

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In the big battle scene that kicks off Gladiator, one of Maximus’s soldiers is of the canine variety—specifically, a German shepherd. In our non-movie world, German shepherds didn’t come into existence as a breed until the late 1800s.

11. THE GREEN MILE (1999)

Though set in 1935, Frank Darabont’s The Green Mile has death by electric chair as Louisiana’s preferred method of execution. The chair would not replace the gallows in that state until the early 1940s.

12. MARIE ANTOINETTE (2006)

An intentional anachronism, this time around: In a scene from Sofia Coppola’s Marie Antoinette, a pair of Converse sneakers can be seen next to more period-appropriate shoes. The goal, per Coppola, was to emphasize Marie Antoinette’s youth; “I didn’t want [the film] to be a history lesson, I wanted it to be more impressionist,” she said.

13. TROY (2004)

Staying in ancient times, we come to Troy—a (very) loose adaptation of Homer’s The Iliad. For this one, director Wolfgang Petersen took llamas, indigenous to South America, and spirited them all the way across an ocean to be plopped down in what is now Turkey. “It is impossible that there would have been llamas in Europe or Asia for at least another 2800 years,” The Guardian’s Alex von Tunzelmann commented. “Unless these ones were really good swimmers.”

14. ROBIN HOOD: PRINCE OF THIEVES (1991)

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In Robin Hood: Prince of Thieves, Azeem (Morgan Freeman) chides Robin (Kevin Costner) for not knowing what a telescope is, asking him “How did your uneducated kind ever take Jerusalem?” But, while more technologically advanced than their British contemporaries, the Islamic world wasn’t that far ahead: telescopes weren’t invented until 1608, about 400 years after Prince of Thieves takes place.

15. QUADROPHENIA (1979)

Quadrophenia, the 1979 cult classic based on the album of the same name by The Who, has its share of anachronisms. Is that a movie marquee advertising Grease and Heaven Can Wait—both released in 1978—in a film set in 1965? And why is someone wearing a Motörhead shirt when the band didn't form until 1975? You know what? It’s rock ‘n’ roll. Just go with it.