Contributed by Paul Seaburn, Catalogs.com Top 10 Guru

There are a lot of things that are mysteries to me: how does a thermos know how to keep hot things hot and cold things cold?

Why do I always sit next to a salesman on the airplane? Why is my head going bald while my ears are getting hairier? But those are small compared to things that have baffled mankind for centuries. While I trim my ears, check out these greatest mysteries in history.

10. Stonehenge – Rocks of Ages

Stonehenge, the circle of large stones nestled in the hills of the English county of Wiltshire, has puzzled archeologists for centuries. The holes for the stones appear to have been dug around 3000 BC, but it was 1000 more years before someone lugged bluestones from 240 miles away in Wales to the site. They appear to have been set up in two circles in alignment with the path of the sun, but who did it and why is still unknown.

9. Loch Ness Monster – What a Ness

“Loch” means lake in Scottish and “Loch Ness Monster” means plenty of tourism to this deep water lake in the Scottish Highlands. First reported by Saint Columba in the 6th century, grainy photographs and movies along with unsubstantiated eyewitness reports make many believe the monster is a dinosaur similar to the plesiosaur. However, no scientific excursion has come up with anything more than a bill for their services.

8. Bermuda Triangle – The Long and the Shorts of It

Draw lines between Bermuda, Florida and Puerto Rico and you’ll see the Bermuda Triangle, an expanse of the Atlantic Ocean where many ships and airplanes have allegedly vanished due to unexplained circumstances. Speculation runs from forces from the lost continent of Atlantis to powers emulating from a crashed UFO. Human error and hurricanes are the more scientific explanations for the disappearances.

7. Atlantis – Real or All Wet?

The Greek philosopher Plato mentions in his dialogues Timaeus and Critias that Atlantis and its powerful navy ruled over parts of Western Europe and Africa around 9600 BC until it failed to invade Athens and sank into the ocean in one day. While Plato’s account could be based on an ancient civilization destroyed by a volcano and would put Atlantis in or near the Mediterranean, both underwater and modern satellite searches have found nothing but shadowy images so far.

6. Shroud of Turin – Shrouded in Mystery

In the Cathedral of St John the Baptist in Turin, Italy, is a linen cloth bearing the image of a crucified man that many believe is the burial shroud of Jesus Christ. It appeared suddenly in the 14th century in France and was moved to Turin in 1578 for safety. Various tests from carbon dating to blood stain and cloth analysis have been conducted on the shroud without any definitive conclusions. The Vatican has no official position on its authenticity.

5. The Great Pyramid – Ask Your Mummy

Forty stories high and made of over 2 million limestone blocks weighing 2 to 5 tons each by some 200,000 workers who hadn’t yet invented the wheel – the Great Pyramid of Giza is definitely a great mystery. The tomb of the Egyptian Pharaoh Khufu was built in 20 years somewhere around 2560 BC. Its construction is an engineering marvel even by today’s standards – and don’t get me started about the Sphinx!

4. Bigfoot – A Really Big Shoe

You can call him Bigfoot or Sasquatch or Yeti or the Abominable Snowman – what you can’t do is catch him. Both the American and Himalayan versions are described as ape-like creatures that stand 6-to-10 feet tall, walk upright on 24-inch feet and are extremely hairy. A famous home movie of Bigfoot was later revealed to be a guy in a gorilla suit by the photographer. While spoor samples, hair samples and footprints have always been proven false, scientific expeditions to find the big fella (it always seems to be a male) continue.

3. Mary Celeste – All Not Aboard

The Mary Celeste was a sailing ship found on December 4, 1872, in the Atlantic Ocean with no one onboard. It was sailing towards the Strait of Gibraltar with a full cargo, it had six months of food and water and all of the crew’s belongings and valuables were stowed in place, but the crew had vanished and was never heard from again. Theories on the ghost ship abound, including piracy, mutiny, fumes from alcohol stored in barrels exploding or the crew abandoning ship in one lone lifeboat.

2. Jack the Ripper – Or Was it Jill?

Perhaps the most famous unsolved serial killing involves the deaths of five prostitutes in London between August and November 1888. The name Jack the Ripper came from a letter from someone claiming to cut the throats and mutilate the victims, but it may have been a fake. The murders were highly publicized but are still unsolved. Among the suspects over the years are doctors and aristocrats, including the future King Edward VIII, and even a woman.

1. King Arthur – Rounding Up His Identity

Pretending to be knights saving fair maidens from dragons wouldn’t be as much fun if we didn’t have the story of King Arthur and the Round Table to use as a guide. Tales of his life and adventures in the late fifth century first appeared in the 12th century book, History of the Kings of Britain, but have never been proven. One theory is that he was a Roman commander named Lucius Artorius Castus who led 5,500 Sarmatians in Britain at the end of the second century.

Would you add another world-class mystery to our list?