Grand Theft Auto is one of the most enduringly popular video games in history. Part of that popularity is, of course, the over-the-top scenarios you find yourself in while playing it. Nothing like a little murder and mayhem in the virtual world. But Rockstar Games has always had a history of adding extras, surprises, secrets, and Easter eggs into their games as an added bonus for fans.

It’s something gaming fans have come to expect. Even if you aren’t looking for secret images, specifically, you’ll catch strange images and impressions as glimpses out of the corner of your eye as you make your way through the GTA game world. Along with introducing some side missions and other direct elements in the game, the secrets also add to the whole legendary world that is GTA.

With Grand Theft Auto 5, they’ve pulled out all the stops, building on the sense of a real world with a history and its own mythology. Some of the material is geared toward the game’s adult audience, including a tour of the Playboy Mansion. Other details, though, are downright creepy and add to the sense of danger and mystery, upping the vibe of your game play.

There have been many secrets and surprises over the years. Here’s a look at 15 of the best.

Solve Vinewood Murder Mystery – Get Vintage Noir Filters

Solving the secret to the Vinewood murder gets you cool vintage noir filters you can use on your phone and in the game. The Murder Mystery is a secret side mission that you can access in the enhanced version of GTA 5, but only if you've already played it on the PlayStation 3 or Xbox 360 versions. You have to play as Michael De Santa, and unlike with other side missions, there's no message that will tip you off first. You just have to get going and find the four clues that are scattered around Los Santos in the form of messages scratched onto the wall. You’ll find them beside the entrance of the Gentry Manor Hotel in West Vinewood, in some trees behind the Oriental Theatre downtown, in an alcove behind City Hall, and in a lower level of the Galileo Observatory in the hills. Together, the four cryptic messages implicate Fred, and lead you to the body of a woman in the water, off the coast near Fort Zancudo. For the next step, you'll need to complete Meltdown mission, in order to get into Solomon Richards's office at Majestic after 21:00. Then, you can read a letter on his desk by Fred Quincy, who killed his secretary (the body in the water) and a man called Isaac. You'll find Isaac’s pinstripe-clad body in a mine shaft in Great Chaparral.

The Hot Coffee Mod

Hot Coffee was the first GTA secret to create a big splash – so big it changed the rules. The game programmers at Rockstar North amused themselves while they were coding the 2004 release Grand Theft Auto: San Andreas by creating a secret mini-game. The Hot Coffee game was completely inaccessible in the original version. However, the Windows port of GTA: San Andreas, released in 2005, included the Hot Coffee mod, which made it accessible. Hot coffee is a euphemism for sex, and that’s what Carl "CJ" Johnson, the lead character in the game, and the girlfriend you chose for him, will do in the roughly animated segment. Intrepid gamers also discovered Hot Coffee in the PlayStation 2 and Xbox versions of the game and hacked their way into it. The raunchy mini-game generated so much buzz that the dreaded authorities got involved, and politicians and the courts saw to it that GTA’s rating was changed to Adults Only (AO) by the U.S. Entertainment Software Rating Board (ESRB). In Australia, it was refused classification altogether, and it was taken off the shelves. In subsequent versions of the game, a mod called Cold Coffee removed the mini-game entirely, and it went back to its former rating.

UV Black Light Secret Messages

If you’ve got the Special Edition of GTA 5, you can access secret messages on the map that you can see only by UV or black light. The hidden messages are located on the back side of the blueprint map. That’s correct – you'll need an actual black light in order to see them on your screen. Some relate to items like hidden spaceship remnants that you’ll need to get 100% completion. One refers you to "T.P.E - Trevor Philips Enterprises. Weaponry, narcotics, intimidation and casual wear." There are directions along with the stipulation, "Bring $500,000 cash." Some locations on the map yield armored cars and even nuclear waste barrels. Other messages are more obscure, like pictures of buildings covered in alien symbols and people practicing yoga on the roof.

Links to Previous Games

Pretty much every version of GTA has referenced previous versions, one way or another. Nike Bellic, the protagonist from GTA IV, gets a pretty obvious mention in Liberty City when Lester talks about “some Eastern European guy” who “went quiet.” But there’s a much more subtle and secretive clue as to Niko’s fate. If you play as Michael, you can spy on Jimmy with the camera, and if you get a look at his laptop, he’s checking out Niko’s Lifeinvader page. Niko’s alive and kicking somewhere out there in cyberspace. You may also bump into a few characters you’ll remember from GTA: San Andreas in the Hood Safari mission. You’ll end up on Grove Street, which is where GTA: San Andreas begins. As you get close to Grove Street, you’ll see three characters on BMXs – it’s CJ, Big Smoke, and Sweet.

Aliens And UFOs

Just after you begin playing GTA 5, during the prologue, and if you’re really quick, you can find a xenomorph Alien. You’ll have to take a speedy detour to the right down the hillside, then across the frozen river to under the bridge. Hop out of the car, and then, look below your feet to find the Alien frozen under the ice. Hop right back in the car and get back on the road as quickly as you can, or your mission will fail out. That’s just the first of several extraterrestrials you can discover in GTA 5. If you take a submarine into the water, towards the northernmost part indicated on the map, and you’ll find a UFO crashed at the bottom of the ocean. The mural at the top of Mount Chiliad, which you can access via cable car, depicts an intriguing diagram. While you can get to it at any time during the game, if you haven't finished it yet, you'll get the message “Come back when your story is complete.” After 100% completion, a UFO will be flying over the mountain. If you overlay the mural over the game map, you'll find the location of peyote plants and Bigfoot, among other things.

Bigfoot And Peyote

Gamers who looked into the game code of GTA 5 found special peyotes, which didn’t follow established patterns and even contained clues left by the programmers. If you went to a specific area of the map, while the weather was foggy or snowy, on a specific day of the week, at a specific time, between 5 AM and 8 AM, you’d find one of the peyotes. The golden peyote, the first found, turns you into Bigfoot. There were actually seven special peyotes, each to be eaten in similar weather, at a specific time, one for each day of the week. If you eat them all, it opens up a mini-game involving Bigfoot and a new beast of the woods. In another Bigfoot sighting, when you’re in the Predator mission, you’ll play as Michael, shooting from out of a helicopter. As you look for heat signatures in the forest, take aim at the one you see in the lower-right screen. It’s Bigfoot. There are many gamer theories out there about the mural and what other secrets it may yet unlock.

The Infinity Killer

One of the reasons for GTA 5's continued popularity over the years has to be the way the programmers incorporated so many layers to the gaming experience. The Infinity Killer mystery is one of those elements. You'll never see Merle Abrahams, the infamous Infinity Killer obsessed with the number 8, during the game, but you’ll hear about him and you can solve a mystery. You can pick up clues to the Infinity Murders, when Merle killed 8 male joggers. Their bodies are hidden around the state, and while they were never found, Merle was arrested and jailed there, and he died there in 2004. During his murder spree, he scrawled messages all over Blaine County that you can find, beginning with the charred ruins of his home in Sandy Shores. More clues are found on rock graffiti in the Bolingbroke Penitentiary, and bloody footprints surround the 8-ball pool table at the Yellow Jack Inn. The 8 bodies can be found on the seafloor near the islands north of Mount Chiliad.

Play As Jack Torrance

GTA 5’s makers used the game to plug their own fanboy causes, including movie references right out of the blue. If you play as Trevor, and you’re a fan of films from the 1970s to 1990s, you may notice that he looks just a little bit like Jack Nicholson. Jack played The Joker in the original Batman movie, but he also played Jack Torrance, the gleefully possessed killer in The Shining, an adaptation of a Stephen King novel. As Trevor, you can buy the Overlooked Red Blouson and don the “Grown Out” hairstyle, and he’s a ringer for Jack Torrance. “Overlooked” refers to the name of the resort Torrance and his family are living in and looking after – the Overlook Hotel. It’s one of the many very subtle secrets in the GTA franchise.

Max Payne Connection

The Max Payne game series was created by Remedy Entertainment and published by Rockstar Games. Various versions of Grand Theft Auto have referenced the series. In GTA 2, released at a time when the original Max Payne game was still under development, one of the garages in Anywhere City went by the name "Max Paynt." In the Tank Commander mission in Grand Theft Auto: San Andreas, if you check out the window of the liquor store, the label on the glass is “Max Pane.” Michael De Santa, from GTA 5, looks a lot like Max Payne, and his story matches – 40-something, depressed, drunk, tortured past. He can also slow down time, just like Max Payne, and he even wears the same gray suit Max wears in Max Payne 3. In the game, you can buy a Hawaiian shirt, leather jacket, and haircut to look even more like Max.

Ghost On Mount Gordo

Jock Cranley is a prominent public figure in GTA. He’s a TV star, a politician, and he lives a glamorous life. He’s also got a very dark side, and you can uncover part of it. If you travel to Mount Gordo between 23:00 and midnight, you’ll see the ghost of Jack’s wife hovering over a rock. The word “Jock” is written across that rock in blood. Turns out, Jock threw his wife off the mountainside back in the 1970s when she tried to nix the idea of moving to Los Santos. Jock was arrested, but the investigation eventually concluded that the death had been accidental. It wasn’t, and his wife’s ghost wants to tell the world about his guilt. If you see the ghost of Jolene Cranley-Evans from behind, you’ll see a black mist swirling around her. It’s one of the creepier experiences in GTA 5.

J. Marston, Author?

The appearance of a book and its author is at the heart of an enduring GTA mystery. In GTA 5, when you're in Franklin’s condo in the Vinewood Hills, check out his bookshelf. You’ll find a blue book with the title “Red Dead,” and the author listed is J. Marston. John Marston was the protagonist in Red Dead Redemption, a Western action-adventure game in the Rockstar catalog released in 2010. Did John fake his death, now making his living as the writer of cheesy genre novels? Or is it Jack Marston, John’s son, who has decided on a life on the straight and narrow? If you're a member of the Rockstar Games Social Club, and you’ve linked your Xbox Live gamertag or PSN username, John Marston also appears in GTA Online as one of your choices as parent when you play the game.

Vinewood Zombie

The world of GTA V includes a classic Vinewood film called Vinewood Zombie. It was produced in 1981 by Richards Majestic Productions. Despite the catchy tagline of "Eating brains in the land of the brainless," it was voted worst movie of 1981. As you drive to the corner of Vinewood Boulevard, you’ll see what looks like a zombie, complete with ghastly face and torn clothes. If you stop and talk to him as Trevor, though, you’ll find out he’s Graham, an actor who’s cosplaying the Vineland Zombie. In fact, he’s got a street hustle going on, talking about zombies and taking pictures with passersby for $10. If you listen to his speech and let him ramble on, he’ll go from bragging about his job to making creepy statements like the fact that he wants to give himself a lobotomy. He may also get a phone call from his mother while you’re talking.

James Bond Car

You can get a ride just like James Bond in Grand Theft Auto V and Grand Theft Auto Online. The Dewbauchee JB 700 option – James Bond 007, get it? – is based on the Aston Martin DB5, favored by Bond in Goldfinger, Skyfall, and other classics. The car’s features are based on British and Italian designs of the 1960s, with front-mounted dual semi-automatic guns, and a V12 engine. That’s just scratching the surface of all the cool details involved. You can get your James Bond ride once you complete the Deep Inside mission, playing as Michael. Look for it on the Legendary Motorsport website. According to a notice, the guns have been (sadly) decommissioned.

Beach Secrets

Los Santos is a thinly veiled reference to Los Angeles, a locale found in GTA: San Andreas and GTA 5. The City of Saints, like the City of Angels, features warm weather and beautiful beaches. But this is GTA, and the beaches hold secrets, too. Vespucci Beach in West Los Santos is modeled after Venice Beach and Santa Monica. Along with Muscle Sands, an open-air gym, it’s where you can find a sand sculpture in the form of a shark, including a surfboard that it’s biting into. If you go for a swim and head for the place where the eastern edge of the map ends, you’ll see the skeleton of a large animal at the bottom of the sea. It looks like a whale or some kind of enormous sea monster.

More Movie Easter Eggs

GTA’s creators peppered the game with references to their fave movies. In GTA 5, if you make your way to the Vinewood Walk of Fame, you can hook up with a Vinewood Star Tours bus for a small charge. Climb aboard and listen as you pass City Hall, where they’re filming a battle as the finale of a movie called “Invasion: Los Santos.” It’s a direct reference to the sci-fi flick Battle: Los Angeles. There’s a nod to the Coen Brothers film, No Country For Old Men if you make your way to Mount Chiliad State Wilderness. North of the highway bridge, you’ll see four smashed up cars, along with several dead bodies that are strewn all over the ground. If you remember No Country, you can score by finding a metallic case filled with $25K in cash just down the hill from the scene of mayhem.

Sources: gamesradar.com; ign.com