There are thousands of volcanos around the world, so selecting the most dangerous is always going to be a subjective affair. For one, the most dangerous volcano clearly depends on where you live: If you live right next to one, such as in a densely populated country like Indonesia, then Mount Merapi or Agung are going to be your pick.

Then you've got to consider that a good number of volcanos have been erupting or spewing lava constantly for decades. There goes the element of surprise ... and as some people around Mount Etna will tell you, you can get used to living under a cloud of impending doom. No, we're not making light of the threat from volcanos. The threat is very real, as people in the Philippines and Papua New Guinea can tell you right now. Mayon in the Philippines and Kadovar have been an active threat since early January. In Russia, Sheveluch has likewise come online.

Also, bear in mind that flowing volcanic lava is not necessarily the biggest threat to life or habitation. Other volcanic emissions, particularly volcanic ash, can travel far greater distances and create far greater threats to life on Earth. Need we mention the dinosaurs? No. 

That being said, this is a list of … let's call them "the usual suspects," with a few curve balls thrown in for good measure. And for argument's sake, the list is alphabetical.

Oh, one more thing: There are various types of volcano. The most common among our list are stratovolcanos, shield volcanos, and calderas.

Stratovolcanos are perhaps the most common. The Global Volcanism Program, which is run by the Smithsonian Institution in Washington D.C., says these are "what most people associate with the word volcano. "These towering peaks rise hundreds to several thousand meters above their surroundings, often visually dominating the landscape."

By contrast, shield volcanoes have a low-angle profile, resembling a warrior's shield. They may not be as visually stimulating as stratovolcanoes, but they tend to be bigger.

Calderas, such as the mega-threat-in-waiting at Yellowstone in the United States, are huge volcanic depressions formed by the collapse of the summit of the flanks of a volcano. They can be as large as 100 kilometers (60 miles) across and the site of "scenic caldera lakes."

Right. Now for that list. Starting with the letter "A" for …  

Agung - Bali, Indonesia

Status: Erupting

Population within 5 kilometers: 5,657

Type: Stratovolcano

Summit: 2997 meters

Agung is Bali's highest and most sacred mountain. It dominates its surroundings visually and influences the local climate. It sucks water from clouds from the west, making the western part of the island green, while the east barren.

Erta Ale - Danakil depression, Ethiopia

Status: Erupting; ongoing since 2005

Population within 5 kilometers: 2,685

Type: Shield

Summit: 613 meters

Erta Ale is renowned for its constant lava lakes. The caldera at Erta Ale's summit has between one and two lava lakes that have been active since the 1960s - and possibly even longer.

Etna - Sicily, Italy

Status: Erupting; ongoing since 2014

Population within 5 kilometers: 78

Type: Complex Stratovolcano(es)

Summit: about 3295 meters and rising (due to current activity)

Mount Etna is considered to be Europe's most active volcano, and second most active in the world after Hawaii's Kilauea. It's certainly the continent's most famous. The local region is known for its citrus orchards, which produce wonderful oranges and lemons. Even the ones with volcanic debris embedded in the skin taste good. 

Eyjafjallajokull - Iceland

Status: Dormant since 2010

Population within 5 kilometers: ~0

Type: Stratovolcano

Summit: 1651 meters

Eyjafjallajökull is also known by its shorter name Eyjafjöll. Either way, it refers to an "island mountain under a glacier." During its most violent phase in 2010, a subglacial eruption produced massive plumes of ash that hung over Europe. It forced the closure of huge swathes of European airspace.

Kadovar - off Papua New Guinea

Status: Erupting

Population within 5 kilometers: ~0

Type: Stratovolcano

Summit: 365 meters

The nearest population over a thousand to Kadovar may be about 30 kilometers away, but residents were reportedly evacuated to nearby Blup Blup island when the volcano on Kadovar began emitting smoke and ash in early January. There is a village called Gewai perched on the crater rim.

Kilauea - United States (Hawaii)

Status: Erupting

Population within 5 kilometers: 3,122

Type: Shield

Summit: 1222 meters

Kilauea volcano has been erupting almost uninterruptedly since 1960. There have been some breaks, with the current eruption having started in 1983. Kilauea overlaps the east flank of the massive Mauna Loa shield volcano. It is a young volcano and is reputed to be Hawaii's most active one.

Krakatau - Sundra Strait, Indonesia

Status: minor activity

Population within 5 kilometers: 7,177

Type: Caldera

Summit: 813 meters

Krakatau is another one of those famous volcanos. It is often referred to as Krakatoa, but that's wrong. It lies between the islands of Sumatra and Java. It is a largely submerged caldera that gave birth to Anak Krakatau ("Child of Krakatau"), a new island, in 1927.

Mayon - Luzon Island, Philippines

Status: Erupting

Population within 5 kilometers: 4,350

Type: Stratovolcano

Summit: 2462 meters

Mayon started spewing lava in mid January 2018. It happens quite regularly, but still, thousands of people live and farm nearby. Officials have warned locals not to enter the danger zone, which encompasses a 6-7 kilometer radius. Mayon's typical eruption style is "explosive." Its most violent eruption was in 1814 and killed more than 1,200 people and destroyed towns.

Merapi - Central Java, Indonesia

Status: minor activity

Population within 5 kilometers: 49,205

Type: Stratovolcano

Summit: 2910 meters

Merapi ("the one making fire") is one of Indonesia's most active volcanoes. It erupts about once every five to ten years, threatening one of the world's most densely populated areas. It lies north of the major city of Yogyakarta. Its style is highly explosive and creates avalanches of hot rocks and gas.

Nyiragongo - Democratic Republic of the Congo

Status: Erupting; reduced activity

Population within 5 kilometers: 2,416

Type: Stratovolcano

Summit: 3470 meters

Situated near Lake Kivu, Nyiragongo is described as one of Africa's most beautiful volcanoes. It held a lava lake in a deep summit crater until it drained through its outer flanks in 1977. A current lava lake has been active since 2002 when a lava flow flooded parts of the major city of Goma, causing some fatalities. A World Health Organization report said it was remarkable that there had been less than 100 deaths in a local population of 500,000.

Pacaya - Guatemala City, Guatemala

Status: Active, last eruption 2016

Population within 5 kilometers: 4,250

Type: Complex volcano

Summit: 2569 meters

When Pacaya erupts, it can be seen from the nation's capital, Guatemala City. It's known as a complex basaltic volcano and has a mildly explosive style. Most of the recent activity there has been lava flows and some violent phases of "lava fountaining."

Sakurajima - Kyushu, Japan

Status: Erupting; ongoing since 1955

Population within 5 kilometers: 4,918

Type: Caldera

Summit: 1117 meters

Sakurajima is contained in the Aira caldera in the north of Kagoshima Bay. It is one of Japan's most active volcanoes — in fact, it is one of the most active in the world and one of the few to currently show constant activity. It has an explosive style. It largest eruption is dated back to 1471.

Sheveluch - Kamchatka, Russia

Status: Erupting

Population within 5 kilometers: ~0

Type: Stratovolcano

Summit: 3283 meters

Sheveluch is highly explosive. Satellite images from January 10 reportedly show an ash cloud over the volcano, prompting new warnings of activity. It follows signs of a "thermal anomaly" detected by Kamchatkan Volcanic Eruption Response Team (KVERT) in December 2017. Other reports cite ongoing activity at Sheveluch since 1999.

Yasur - Vanuatu

Status: Erupting

Population within 5 kilometers: 3,636

Type: Stratavolcano

Summit: 361 meteres

Yasur is the most famous of the Vanuatu volcanos. It has shown almost uninterrupted activity since Captain Cook observed ash eruptions there in 1774. It is known for "strombolian" activity, which is characterized by small but sometimes violent explosions from one or more vents.

Yellowstone - Wyoming, United States

Status: Dormant

Population within 5 kilometers: ~0

Type: Caldera(s)

Summit: 2805 meters

Yellowstone's last known eruption was in 1350 BC, but volcanologists say it presents a near-constant threat. The Yellowstone Plateau has three calderas and forms one of the largest volcanoes in the world. Its magma chamber is thought to be active and estimated to hold at least 15,000 cubic kilometers of melt. It's just one of the reasons some people fear Yellowstone is a super-volcano waiting to happen!