With the billions of dollars being spent on blockbuster films, it's hard to watch an epic action, fantasy, or science fiction movie just once. But even with repeat viewings, some awesome or unbelievable details always seem to slip by viewers' eyes.

We're determined to fill fans in on every cool easter egg or inside reference, so we hope you enjoy Screenrant's 10 Amazing Hidden Details in Movies.

Pearl Harbor

Pearl Harbor Die Hard Bruce Willis Easter Egg

Plenty of cash was spent on the special effects of Pearl Harbor, but apparently, either director Michael Bay or the special effects team decided they still had room for some fun. Once the movie made it to home video, fans starting noticing a standout extra among the wounded sailors. As strange as it may seem, it appears that Bruce Willis' tough-as-nails cop John McClane has been spliced out of Die Hard, and into the WWII-era drama. Since the footage of a bruised, battered McClane in an undershirt isn't an exact match to any Die Hard scene, some skeptics say it's all coincidence. But the size and perspective shows it's clearly an added digital effect, and one that can never be missed once it's pointed out.

The Matrix

Best Action Movies The Matrix

Most fans of The Wachowski's game-changing sci-fi series know that The Matrix's plot forms a perfect circle: the hotel and room 303 where the movie begins is also the same place where Neo becomes "The One." But fans probably missed an even bigger example. The first movie ended with a serious phone call, as Neo told the Machines that he planned on freeing humanity.

Two sequels followed, but when Neo finally ended the war in his epic battle with Agent Smith, their fight is set at that exact intersection. When the two slam into the street, you can even catch a glimpse of the phonebooth from the first film.

Iron Man

Iron Man Big Lebowski Easter Eggs

Tony Stark found out the hard way that even friends can't be trusted, when his business partner Obadiah Stane revealed he was funding terrorists (and building his own suit of armor). But Iron Man should have known he was up to no good long before. When Tony finds Stane playing some piano in his Malibu mansion, it's not a random bit of music, but a sample of Antonio Salieri's "Piano Concerto in C." Music buffs, or those who saw the movie Amadeus will get the hint, since Salieri was long rumored to have sabotaged and killed Mozart. The composers' rivalry wasn't anywhere close to Stark and Stane's, but the hint was there all along.

The LEGO Movie

Best Animated Movies Lego Movie

Directors Chris Miller and Phil Lord beat the odds when they made a movie about LEGO a worldwide hit. The film even included Superman and Green Lantern, played by Channing Tatum and Jonah Hill, the stars of their previous surprise hit, the rebooted 21 Jump Street. It wasn't the only nod to the story of undercover cops, though. When Emmet's apartment is first shown, a poster can be seen advertising the movie "Teen Copz," an obvious reference to Jump Street.

But the poster next to it takes the cake, since the Tatum/Hill comedy really was sold to Russian audiences as "Macho and the Nerd."

Harry Potter and The Goblet of Fire

Dumbledore looking intently in Harry Potter and the Goblet of Fire

For those not versed in Harry Potter mythology, we'll just say that to bring down Lord Voldemort, the three Deathly Hallows were sort of an important combination. It wasn't until the second last book that audiences learned that a cloak, stone, and Elder Wand held the key to victory, but the idea was teased ahead of time. As in, two full movies ahead of time. In one of the franchise's best easter eggs, Dumbledore tells Harry that he's been searching for such a detail that held the secret to defeating Voldemort - but the answer is literally right in front of him, in the form of a 3D version of the Deathly Hallows symbols stored in his own office.

Mission: Impossible - Ghost Protocol

mission impossible ghost protocol dangerous movie stunts tom cruise actually performed

Every fan of Disney and Pixar knows to keep an eye out for the code "A113," the room number that the studio's top animators all studied in when attending the California Institute of the Arts. But it doesn't stop at animated movies. When Brad Bird graduated from directing movies like The Incredibles and Ratatouille to Mission Impossible Ghost Protocol, he made sure to give a nod to his roots. Watch closely, and you'll spot the code on a trick ring used by IMF agents to inject a sleeping drug into their unsuspecting target.

The Hunger Games: Catching Fire

An image of Katniss standing in front of media screen in Mockingjay - Part 1

The Hunger Games series took a major step up in budget and spectacle with its second instalment, but not every addition was taken completely seriously. When Katniss and Peeta are heading out to make their grand entrance before the next games, the doorway they pass under is clearly marked with the code "PDL-736." The meaning isn't complicated, it's just an address: 736 Ponce de Leon Avenue, a club that the cast would frequent when filming in Atlanta, Georgia.

Man of Steel

Henry Cavill as Superman in Man of Steel

Zack Snyder and Warner Bros. wanted to make a clean start with Man of Steel, but that didn't mean the director wanted to ignore the version of the DC hero who came before, specifically, the original films from director Richard Donner. The updated version of the ship that brought Kal-El to Earth played a big part in the story, but when Kal-El had his escape explained by his (digital) father Jor-El, the version of the ship shown is obviously modeled after Donner's version, not Snyder's.

The Avengers: Age of Ultron

Captain America Chris Evans No Superhero Movie Fatigue

It wasn't just powerful fighters or alien invaders that Marvel's Avengers had to tackle in their second team-up, but a girl who could force them to face their worst fears, or tempt them with a better life. For Captain America, that meant sending him back to a USO soiree before he was frozen for decades. Pay attention to the band though: the Roy Thomas Players aren't named after a musician, but a Marvel Comics legend.

Roy Thomas spent years writing X-Men, Avengers, Doctor Strange, and even created modern characters like Adam Warlock and Vision, who makes his movie debut in the same film.

Star Trek Into Darkness

Khan Star Trek - Most Powerful Villains

Before Chris Hemsworth was famous as the Marvel hero Thor, he splashed onto the scene playing Captain Kirk's father George in Star Trek. The 2009 reboot saw George killed in battle aboard the USS Kelvin, but his legacy, and that of the ship, lived on. In the sequel, fans were probably too busy trying to make sense of the bomb plot and blood transfusions to notice that the scene of the disaster was the Kelvin Memorial Archive. Named for Kirk's ship, it means the destruction of the Kelvin set the plots of both films in motion - a subtle nod that only the diehard fans might have caught.

Conclusion

So what do you think of our list? Did we miss any of your favorite easter eggs, obscure references or hidden secrets? Let us know in our comment section and don’t forget to subscribe to our channel for more videos like this one.