Sprawling across a slice of Massachusetts, the Bridgewater Triangle covers some of the most foreboding and mysterious terrain you can imagine. Think vast bleak wetlands and wooded zones large and dense enough to get lost in. This is the area that gave rise to one of the very first UFO sightings: way back in the year 1760, onlookers reported a "sphere of fire" so brilliant that it was seen across several towns.
In 1908, a pair of undertakers travelling on a carriage reported a flying object they likened to "an unusually strong lantern". Other witnesses corroborated their story, some assuming it was a hot air balloon. The undertakers didn't agree, with one writing: "I claim that a hot air balloon could not move in a circle or perpendicular as this one did."
Since then the tales of inexplicable phenomena have come time and again in the Bridgewater Triangle, including sightings of cryptozoological creatures such as Bigfoot and "thunderbirds" - huge flying animals of American myth. Mutilations of livestock have also been reported in the forests.
Over in Vermont, another geographical area has become notorious: the Bennington Triangle, which covers the craggy landmark of Glastenbury Mountain and ghost towns. The town of Glastenbury itself had a population of 8 according to the 2010 census, which gives you an idea of how quiet and isolated the area is.
The Bennington Triangle has been the setting for a number of unexplained disappearances over the years. They began in 1945, when local man Middie Rivers was leading a group of hikers near the mountain. He walked ahead of the group and seemingly vanished into thin air. The very next year, teenager Paula Welden was hiking in the same area when she disappeared, triggering a media storm and massive hunt which didn't turn up any clues.
Some years later, a young boy named Paul Jepson was told to wait in his mother's car while she visited a site near the mountain. She returned to an empty vehicle. Another huge search was launched, with hundreds of volunteers scouring the area to no avail. Both Paul and Middie had been in red clothes when they vanished, leading to a superstition that it's bad luck to wear red and visit Glastenbury Mountain. Further vanishings, along with numerous UFO sightings, have made this a magnet for paranormal investigators and anyone with a taste for the unusual.
The Bermuda Triangle is located in the Atlantic Ocean, but the Pacific has its own equivalent, dubbed the Dragon's Triangle. Also known to some as the Devil's Sea, this is an area of water just off the coast of Japan, which has been linked to numerous stories of ship disappearances, UFO sightings and magnetic anomalies.
The most disturbing stories focus on Japanese military vessels that vanished in the Triangle in the 1950s, leading to researchers being sent in to see what was going on - apparently, they in turn vanished themselves. Some writers even argue that there are accounts of disappearances on this stretch of ocean going back to the Mongol Empire.
Stretching out for over 300 miles, Lake Michigan is one of the grandest bodies of water on Earth. It's also in the ominous embrace of the so-called Michigan Triangle, which has been linked to yet more eerie aerial sightings and alleged disappearances that have inspired tales across the decades.
The first mysteries were spoken of back in the 19th Century, with boats frequently going missing on the lake. One famous "victim" of the Triangle was the Rosa Belle, a double-masted vessel which was found capsized on the lake with no trace of the crew. Her reptured stern indicated that she had been rammed by another vessel, but no other ship reported any such accident.
In 1937, Captain George Donner vanished from a freighter sailing through the Triangle. The captain retired for the evening to his cabin, asking to be awoken when they neared their end point. Hours later, a crewman went to do just that - to find the cabin empty and the captain gone. The mystery was never solved.
Planes have also been inexplicably downed in the Michigan Triangle, including one of the worst passenger airline crashes in US history. As with all such Triangles, many will argue that the stories have been exaggerated by conspiracy-mongers. But others will maintain that something strange is indeed happening in various hotspots across the world.
Here in Britain we shouldn't feel left out of all these spooky goings-on. After all, we have our very own Matlock Triangle, a zone in the Derbyshire Dales which some have been calling the UFO capital of the world. Numerous stories have circulated about odd, glowing objects hurtling over the Dales, from cigar-shaped aircraft to one shaped "like a bowler hat".
One of the most widely-reported sightings was made by Sharon Rowlands, a local woman who considered herself a "complete and utter disbeliever" until she set eyes on a giant colourful disc hovering over her village. Rowlands caught the incident on her camcorder, and reportedly sold the footage to a US TV company for a handsome sum.
As with the more famous Bermuda Triangle, controversy still rages over whether these are simply tall tales based on misinformation and bad science, or whether weird events really have occurred on these choppy waters.