Theories on the monster include a plesiosaur, a prehistoric creature
Since the Dark Ages, stories of the Loch Ness Monster have thrilled and intrigued the public.
Nessie has gone on to inspire Hollywood, monster hunters and the advertising world.
On the video sharing website, YouTube, a search for the Loch Ness Monster offers more than 2,000 clips.
On the 75th anniversary of the first photograph of a mysterious shape on the loch, here are some of the stories, films, adverts and theories.
In 565 AD, St Columba is said to have crossed paths with the Loch Ness Monster during his journey to Inverness to meet a Pictish king.
Following an attack on one of his party, he commanded the creature to return to where it had come from and it disappeared under water.
In 1933, Mr and Mrs George Spicer told newspapers they saw a monster, measuring 40 to 50 ft (12 to 15m) long, crossing the road near the loch.
The following year, Col Robert Wilson claimed to have taken a photograph of the monster but the famous image was a hoax.
A whole host of films have been inspired by the legend.
They include the 1970 film The Private Life of Sherlock Holmes, also Scooby Doo and the Loch Ness Monster, Loch Ness - which starred Cheers actor Ted Danson, Incident at Loch Ness and The Water Horse: Legend of the Deep.
Sherlock Holmes has been caught up in the Nessie mystery
The monster has also provided material for horror.
Beneath Loch Ness and made-for-TV horror Beyond Loch Ness are among them.
The latter was produced by Canada's Insight Film Studios. It follows a cryptozoologist's hunt for man-eating Nessie years after it killed his father during an ill-fated trip on Loch Ness.
There have been several hunts on Loch Ness.
In 1992, hi-tech sonar equipment was used to search for the Loch Ness monster.
With military-style surveillance technology and backed by a range of experts, a research team began a full-scale search of the loch.
In July 2003 BBC programme-makers carried out the most extensive search yet using 600 separate sonar beams and satellite navigation technology - but found nothing.
The television industry also has a taste for Nessie from the cuddly cartoon The Family Ness to Dr Who - Terror of The Zygons.
Tom Baker as Dr Who faced off rubber monsters in the 1975 episodes of the science fiction series.
The Zygons' spaceship was hidden at the bottom of Loch Ness
Oil rigs are attacked by a huge cyborg, the Skarasen, controlled by a group of aliens called Zygons whose spaceship lies at the bottom of Loch Ness.
The Zygons plan to take over the Earth as a substitute for their own planet, which has been devastated by solar flares. But the Doctor and his assistants get the better of them.
Nessie has also made an appearance in The Simpsons.
Toyota, Abercrombie & Fitch, Orange, Vodaphone, Ballygown Spring Water and Kit Kat have drawn on the loch and its famous resident for commercials.
The advert for Toyota sees the monster grab one of its vehicles from the shores of Loch Ness, disappear beneath the surface, before spitting it back out.
Another for the car manufacturer sees a jogger lured to the water's edge by a life-sized cut out of one of its products, before he is snatched by the beast.
Metres of videotape and thousands of pixels-worth of digital footage have been shot of the monster by people who genuinely believe in Nessie, those just having a bit of fun and hoaxers.
One offering from 2007 and posted on YouTube shows the beast leaping from the water like a playful dolphin.
NESSIE THE ELEPHANT
Theories abound about what the monster is, or was.
Neil Clark, curator of palaeontology at Glasgow University's Hunterian Museum, spent two years researching Nessie and suggested sightings may have been of elephants enjoying a swim.
He said they could have been circus elephants, as fairs visiting Inverness would often stop on the banks of Loch Ness to give the animals a rest.
An escaped elephant may have spawned monster stories
The trunk and humps in the water would bear similarities to some of the most famous Nessie photographs.
Others believe it was a member of the prehistoric group of marine creatures called plesiosaurs, which have been extinct for more than 100 million years, or a massive fish called a sturgeon.
Birds, otters, deers, seals, logs, gas bubbles arising from decomposing matter, waves and the wake of boats have also been suggested as more mundane explanations.