Most of us like to enjoy a good mystery film once in a while. While some of them are laced with elements of suspense that gradually reveal themselves, others do not necessarily have easy answers. The clues in them are covered, tip-offs withheld and the truth obscured. What stands out in such films is the ultimate outcome. It is one that does not have a plausible explanation, only leading the audience to scratch their heads in disbelief.

In this article, we list five movies that were based on unsolved mysteries:

All Good Things (2010)
Andre Jarecki's film, All Good Things, is a love story and a murder mystery that is based on an unsolved murder case in New York.

David Marks (Ryan Gosling), leaves his father's wealth to elope with Katie (Kirsten Dunst), the love of his life. The two want to make a good life. However, David's father, Sanford Marks (Frank Langella), has plans of his own.

David and Katie try to adjust to their new life, but they continue to grow apart. One fine day, Katie vanishes.

Zodiac (2007)
Zodiac, directed by David Fincher, is based on a book by Robert Graysmith. It is about a serial killer who was roaming loose on the streets of San Francisco in the late '60s. He taunts the police with his letters and cryptic messages. While the police were unable to find the killer, two journalists took it on themselves to solve the mystery.

Many suspects were named. One was almost zeroed in. However, due to lack of evidence, he could not been incriminated.

Till today, there are several individuals who confess to being the still-not-caught serial killer.

Memento (2000)
Memento has been directed by Christopher Nolan. The film revolves around an ex-insurance investigator from Carson named Leonard (Guy Pearce) who can no longer build new memories, as he attempts to find the murderer of his wife, which is the last thing he remembers. He has to write himself note after note that still don't mean anything after he falls asleep.

John G is the man he believes has killed his wife. It is a name he has tattooed on his body. Leonard is assisted in the mission by a few people seemingly independent of each other, including a man named Teddy (Joe Pantoliano) and a woman named Natalie (Carrie Anne Moss). However, each time he meets them, he has no idea who they are, why they are helping him and if they are working toward the same goal.

The Vanishing (1988)
This Dutch-French thriller film is about a couple that stops at a fuel station while driving through a road in France. The girl, walks into the store to never return. Her partner, while looking for her, receives postcards from a man that claims to be the perpetrator behind this.

To know what happened to her, he has to strike a deal with the abductor. He has to experience what she went through.

The Birds (1963)
Alfred Hitchcock's, The Birds, tells the story of an unexplained phenomenon which shakes the coastal town of Bodega Bay to its core.

A rich socialite, Melanie Daniels (Tippi Hedren), drives about an hour north of San Francisco to Bodega Bay. Post her arrival, the birds in the area begin to act strangely. A seagull attacks Melanie as she is crossing the bay in a small boat. Thereafter, the birds attack anyone they find outdoors. There is no explanation as to why this is happening. But one thing is for sure – survival is priority.