1) Yellowstone Caldera, USA
This volcano can spread lave over 40 miles and it an go as far as New york and this would poison all the vegetation in the USA. This mountain has not erupted in 640,000 years but it is still active.
2) Mt. Vesuvius, Italy
This is like Yellowstone, it may never erupt to its full force but if it did it would kill millions of people including all the tourists in Pompeii.
3) Popocatépetl, Mexico
This one is just about 40 miles from Mexico City home to over 18 million people. It has erupted about 18 times in the last 500 years the last one being in 1947.
4) Sakurajima, Japan
This volcano had been domarnt for hundreds of years but woke up in 1914 and eruoted spreading lava from the Japan coast of Sakurajima to the mainland.
5) Galeras, Colombia
In 1993, Pasto, Columbia was home to a conference on the most dangerous volcanoes in the world, and the highly-active Galeras erupted during the conference and killed six scientists and three tourists who were examining the crater.
6) Mt. Merapi, Indonesia
This one erupted in 2010 for about two months straight and killed about 353 people. Most of the people died due to the exposure to the heat cloud.
7) Mt. Nyiragongo, DRC
This one has the largest lave lake in the world. It has lava flowing at about 60mph and it has erupted about 34 times in a hundred year with its most recent eruption being in 2002.
8) Ulawun, Papua New Guinea
This volcano also has weak slopes and just in case of an eruption there would be landslides too. It releases about 2% sulfur dioxide which makes it the stinkiest volcano in the world.
9) Mt. Rainier, USA
Rainier is 54 miles from Seattle and is potentially deadly on account of its massive size and the large amount of ice trapped in its glaciers. If it erupted, flows of lava and ice (called lahars) would devastate Washington and possibly unleash tsunamis.
10) Taal Volcano, Philippines
This mountain has erupted about 33 times in the last 500 years and has killed over 6,000 people in the same period. It is just 30 miles from the capital Manila which houses over 1.6million people.