David Goggins
Former Navy Seal
Career Development
Bryan Cranston
Critical Thinking
Liv Boeree
International Poker Champion
Emotional Intelligence
Amaryllis Fox
Former CIA Clandestine Operative
Chris Hadfield
Retired Canadian Astronaut & Author
from the world's big
Start Learning

Behold Sicily's Mount Etna — its volcanic summit is the world's only decipoint

The summit of Europe's most active volcano is also the world's only decipoint.

Ten Sicilian communes converge on the summit of Etna

Image courtesy of Patrick McGranaghan
  • For millennia, Etna has been Europe's most active volcano.
  • The Sicilian mountain is also the world's only decipoint.
  • Ten municipalities meet at its summit — at least on a map.

Geological hotspot

Etna's summit is surrounded by a vast moonscape, 'refreshed' by frequent eruptions

Image: Hein56didden / CC BY-SA 3.0

Mount Etna, in eastern Sicily, almost never sleeps. It's Europe's most active volcano and has been for millennia. For the ancient Greeks, it was the location of the mythical forges of Hephaestus, the god of blacksmiths.

Etna is Italy's highest peak south of the Alps, although the exact height of its summit (currently 10,912 ft, or 3,326 m) varies due to eruptions. Covering an area of 459 sq mi (1,190 km2), it's also the largest of Italy's three active volcanoes (the others being Vesuvius and Stromboli). That gives the locals a lot of room to play cat and mouse with its destructive lava flows.

A string of towns garland Etna, its inhabitants attracted by the volcanic debris that crumbles into fertile soil for the orchards and vineyards on its lower slopes. But Etna takes as well as it gives. Over the centuries, many of those towns have been destroyed again and again by the restless mountain.

But Etna is not just a geological hotspot, it's also a unique place on the map. Zoom in, and you see a bunch of lines converge on its summit. The very tip of Mount Etna is the meeting point of ten Sicilian municipalities. That makes it the only decipoint in the world.

'Four Countries Point'

Early 20th century postcard, showing Belgium, Netherlands, Germany and Neutral Moresnet meeting at a Vierl\u00e4nderpunkt in Vaals.

The bizarre territorial fragment of Neutral Moresnet on an early-20th-century postcard.

Image: public domain

To provide a sense of how rare that is, imagine this: there are hundreds of international tripoints in the world – places where the borders of three countries meet. But increase the number of countries by one, and that number falls to… zero.

That's right, there are no international quadripoints in the world, although for a hundred years, the world did have one. At the Vierlandenpunt ('Four Countries Point') in Vaals, the Netherlands, Germany, Belgium and Neutral Moresnet met (see also #41). But the latter territory was abolished after World War I, reducing Vaals to a rather workaday Drielandenpunt.

In the current geopolitical landscape, one other point comes close: at the eastern tip of Namibia's Caprivi Strip, where it borders Zambia and Botswana, about 200 meters in the Zambezi River separate Namibia from Zimbabwe. But for that distance, the river would contain the world's only current international quadripoint.

Middle of nowhere

Plaque marking the meeting point of Utah, Colorado, New Mexico and Arizona, at Four Corners Monument.

In the middle of nowhere, four states meet

Image: Phil Konstantin / CC BY-SA 3.0

Go down an administrative level, and of course you have the famous Four Corners – the meeting point of the U.S. states of Utah, Colorado, New Mexico, and Arizona. The monument, in the middle of nowhere, provides you with the opportunity of standing in four states at the same time — though, for some (who shall remain nameless), that thrill does not outweigh the long desert ride to get there.

It's the only such state-level point in the U.S. At lower administrative levels, quadripoints are not that rare; but again: add a number and the numbers drop vertiginously. The U.S. has only one county-level quintipoint, for example: the middle of Lake Okeechobee in Florida is where Okeechobee, Palm Beach, Hendry, Glades, Okeechobee and Martin counties meet.

Only one in the world

Map showing the ten communes converging on the summit of Mount Etna

Mount Etna - a natural and cartographic wonder

Image courtesy of Patrick McGranaghan

Double that figure, and there's only one point like it in the world: the summit of Mount Etna. As this map shows, 10 communes reach out to touch the top of the mountain (and each other). Here's a brief description of each, clockwise from top:

  • Randazzo (population 11,000) is a municipality in two parts: the main one touching the summit of Etna, and a large exclave called Spanò (on the left of the map, also in green). Up until the 16th century, the city was trilingual, with Greek spoken in the San Nicola district, Latin in Santa Maria and Lombard in San Martino.
  • Castiglione di Sicilia (pop. 3,000) is listed as one of Italy's most beautiful towns. When Arabs ruled the region, they raised crocodiles in the nearby Alcantara River. Following the Allied landing in WWII, Castiglione di Sicilia was the first town in Italy to be looted by the retreating Germans, who also massacred 16 locals.
  • The small town of Sant'Alfio (pop. 1,500) is famous for the fine, dark wine produced by its vines; and for the Chestnut of a Hundred Horses, a tree up to 4000 years old. It derives its name from the legend that its ample crown once sheltered Queen Joan of Anjou and a hundred of her knights during a storm.

Holiday destination

View of Castiglione di Sicilia

Image source: Salvo Curcuruto / CC BY-SA 2.0

  • Known as the "Pearl of the Etna," Zafferana Etnea (pop. 10,000) is located halfway between the summit and the sea, its cool climate making it a favorite holiday destination on hot summer days. The name most likely derives from the cultivation of saffron in the area.
  • Because of its strategic position between the sea and the summit, Nicolosi (pop. 7,500) is known as the Porta dell'Etna. The town's name probably comes from that of the Benedictine monastery of San Nicoló, one of many built in the area. The earliest one, San Leone, was buried by lava in the mid-16th century.
  • Belpasso (pop. 28,000) is home to Etnaland, the largest waterpark in southern Italy; and Etnapolis, Italy's fifth-largest shopping center. Rebuilt in 1694 in a grid of straight streets, it is known as the "chessboard of the Etna."
  • Biancavilla (pop. 23,000) was founded in the late 15th century by Albanians fleeting Ottomans. A marian icon brought over by the original settlers is still venerated by the townspeople. The presence of opposing mafia clans contributes to the relatively high local crime rate.

The Thunderer

Lava flow from Etna during an eruption in January 2011.

Image: Cirimbillo / CC BY-SA 3.0

  • Adrano (pop. 35,000 inhabitants) was founded around 400 BC by Dionysus, the Greek tyrant of Syracuse. A Saracen bridge and a Norman castle testify to the town's varied history.
  • Bronte (pop. 19,000), 10 miles (16 km) from Etna's summit, is named after 'the Thunderer', one of the cyclopes from Greek mythology said to live under the volcano. In 1799, Britain's admiral Nelson was created Duke of Bronte by King Ferdinand III of Naples, in gratitude for his help in suppressing a revolution and recovering Ferdinand's throne
  • Almost entirely surrounded by Bronte, the little town of Maletto (pop. 4,000) touches eight other municipalities via the decipoint at Etna's summit. Its origins date back to a castle built in the 13th century by Manfredi Maletta, a relative of Emperor Frederick II. For the three-day Strawberry Festival held each June, the locals produce a giant strawberry cake of over a thousand kilos.

Another decipoint?

A number of territorial claims converge on the South Pole

Image: Lokal_Profil / CC BY-SA 2.5

Due to Maletto's semi-enclaved situation, you could argue that not 10 but 11 separate territorial units meet at Etna's summit. Either way, it's a lot. The reason for this unique situation is the active volcanic state of the mountain. This renders the summit and large areas around it virtually impassable. Yet municipal authority, like nature itself, abhors a vacuum. So the surrounding towns set their limits not where their houses or fields end — those limits would be variable anyway, due to the vagaries of the mountain — but at the furthest possible point: the mountain's top.

Some will say that a similar situation occurs at the South Pole, where various, partly overlapping claims have also created a decipoint. But since the Antarctic Treaty of 1961 has effectively frozen all territorial claims in Antarctica, that decipoint at the bottom of the world is a decidedly theoretical one. To visit the world's only "live" one, climb the roof of Hephaestus's forge, and pray he's not about to beat on his anvil.

Decipoint map reproduced with kind permission of Patrick McGranaghan.

Strange Maps #992

Got a strange map? Let me know at

Hulu's original movie "Palm Springs" is the comedy we needed this summer

Andy Samberg and Cristin Milioti get stuck in an infinite wedding time loop.

  • Two wedding guests discover they're trapped in an infinite time loop, waking up in Palm Springs over and over and over.
  • As the reality of their situation sets in, Nyles and Sarah decide to enjoy the repetitive awakenings.
  • The film is perfectly timed for a world sheltering at home during a pandemic.
Keep reading Show less

Two MIT students just solved Richard Feynman’s famed physics puzzle

Richard Feynman once asked a silly question. Two MIT students just answered it.

Surprising Science

Here's a fun experiment to try. Go to your pantry and see if you have a box of spaghetti. If you do, take out a noodle. Grab both ends of it and bend it until it breaks in half. How many pieces did it break into? If you got two large pieces and at least one small piece you're not alone.

Keep reading Show less

Our ‘little brain’ turns out to be pretty big

The multifaceted cerebellum is large — it's just tightly folded.

Image source: Sereno, et al
Mind & Brain
  • A powerful MRI combined with modeling software results in a totally new view of the human cerebellum.
  • The so-called 'little brain' is nearly 80% the size of the cerebral cortex when it's unfolded.
  • This part of the brain is associated with a lot of things, and a new virtual map is suitably chaotic and complex.

Just under our brain's cortex and close to our brain stem sits the cerebellum, also known as the "little brain." It's an organ many animals have, and we're still learning what it does in humans. It's long been thought to be involved in sensory input and motor control, but recent studies suggests it also plays a role in a lot of other things, including emotion, thought, and pain. After all, about half of the brain's neurons reside there. But it's so small. Except it's not, according to a new study from San Diego State University (SDSU) published in PNAS (Proceedings of the National Academy of Sciences).

A neural crêpe

A new imaging study led by psychology professor and cognitive neuroscientist Martin Sereno of the SDSU MRI Imaging Center reveals that the cerebellum is actually an intricately folded organ that has a surface area equal in size to 78 percent of the cerebral cortex. Sereno, a pioneer in MRI brain imaging, collaborated with other experts from the U.K., Canada, and the Netherlands.

So what does it look like? Unfolded, the cerebellum is reminiscent of a crêpe, according to Sereno, about four inches wide and three feet long.

The team didn't physically unfold a cerebellum in their research. Instead, they worked with brain scans from a 9.4 Tesla MRI machine, and virtually unfolded and mapped the organ. Custom software was developed for the project, based on the open-source FreeSurfer app developed by Sereno and others. Their model allowed the scientists to unpack the virtual cerebellum down to each individual fold, or "folia."

Study's cross-sections of a folded cerebellum

Image source: Sereno, et al.

A complicated map

Sereno tells SDSU NewsCenter that "Until now we only had crude models of what it looked like. We now have a complete map or surface representation of the cerebellum, much like cities, counties, and states."

That map is a bit surprising, too, in that regions associated with different functions are scattered across the organ in peculiar ways, unlike the cortex where it's all pretty orderly. "You get a little chunk of the lip, next to a chunk of the shoulder or face, like jumbled puzzle pieces," says Sereno. This may have to do with the fact that when the cerebellum is folded, its elements line up differently than they do when the organ is unfolded.

It seems the folded structure of the cerebellum is a configuration that facilitates access to information coming from places all over the body. Sereno says, "Now that we have the first high resolution base map of the human cerebellum, there are many possibilities for researchers to start filling in what is certain to be a complex quilt of inputs, from many different parts of the cerebral cortex in more detail than ever before."

This makes sense if the cerebellum is involved in highly complex, advanced cognitive functions, such as handling language or performing abstract reasoning as scientists suspect. "When you think of the cognition required to write a scientific paper or explain a concept," says Sereno, "you have to pull in information from many different sources. And that's just how the cerebellum is set up."

Bigger and bigger

The study also suggests that the large size of their virtual human cerebellum is likely to be related to the sheer number of tasks with which the organ is involved in the complex human brain. The macaque cerebellum that the team analyzed, for example, amounts to just 30 percent the size of the animal's cortex.

"The fact that [the cerebellum] has such a large surface area speaks to the evolution of distinctively human behaviors and cognition," says Sereno. "It has expanded so much that the folding patterns are very complex."

As the study says, "Rather than coordinating sensory signals to execute expert physical movements, parts of the cerebellum may have been extended in humans to help coordinate fictive 'conceptual movements,' such as rapidly mentally rearranging a movement plan — or, in the fullness of time, perhaps even a mathematical equation."

Sereno concludes, "The 'little brain' is quite the jack of all trades. Mapping the cerebellum will be an interesting new frontier for the next decade."

Economists show how welfare programs can turn a "profit"

What happens if we consider welfare programs as investments?

A homeless man faces Wall Street

Spencer Platt/Getty Images
Politics & Current Affairs
  • A recently published study suggests that some welfare programs more than pay for themselves.
  • It is one of the first major reviews of welfare programs to measure so many by a single metric.
  • The findings will likely inform future welfare reform and encourage debate on how to grade success.
Keep reading Show less

Unhappy at work? How to find meaning and maintain your mental health

Finding a balance between job satisfaction, money, and lifestyle is not easy.

Scroll down to load more…