There are 1,500 active volcanoes in the world, but these five pose some of the biggest threats to human life, according to AccuWeather.
Galeras is the most active volcano in Colombia. A city of nearly half a million residents sits on the mountain's eastern slope.
Sakurajima was a separate island until a 1914 eruption connected it to Japan's mainland. It sits near a city of more than 700,000 people.
Popocatepetl is just 35 miles away from Mexico City and the 18 million residents throughout the city's metro area.
Italy's Mt. Vesuvius famously destroyed Pompei and Herculaneum nearly 2,000 years ago. The region is now home to 3 million people.
Yellowstone may be home to stunning geothermal features, but a ticking time bomb lurks below. Its power can devastate half the United States.