Volcanoes have shaped some of the world’s most productive landscapes, leaving behind fertile soils, natural harbors and landscapes that have supported communities for centuries. The same geological forces that enrich the land also create threats that can return with little warning. Around the world, millions of people continue to live beneath active volcanoes, accepting the risks because their homes, livelihoods and local economies are closely linked to these landscapes. WorldAtlas lists cities that could face repeated ash falls, while others are concerned about flows of lava, toxic gases or destructive mudflows that could travel miles from the summit.Modern surveillance systems have improved early warning capabilities, but they cannot eliminate the threat. These cities reflect the delicate balance between opportunity and risk, showing how communities have adapted their daily lives to some of the most active volcanic regions on Earth.
Cities built in the shadow of an active volcano
| City | Country | nearby volcano | Main volcanic hazards |
| Orting | United States of America | mount rainier | Lahars (volcanic mudflows) |
| total | United States of America | Mount St. Helens | Mud flows and volcanic sediments |
| the great Lakes | United States of America | Long Valley Caldera/Mammoth Mountain | Carbon dioxide emissions, earthquakes and possible explosions |
| pahoa | United States of America | Kilauea | Lava flows and fissure eruptions |
| Kagoshima | Japan | sakurajima | Ash fall, explosive eruptions and volcanic rocks |
| naples | Italy | Mount Vesuvius and Campi Flegrei | Pyroclastic flows, ash falls and massive eruptions |
The world’s most dangerous cities built in the shadow of active volcanoes
Orting, Washington
Orting is located in a wide valley formed by rivers flowing from Mount Rainier, south of Seattle. The scenery is peaceful, fields spread across rich volcanic soil, but geologists know that the ground beneath the city tells an older story. Much of the community stands on deposits left by a giant wave that swept through the valley some five centuries ago.Unlike lava, lahars behave more like fast-flowing wet concrete. They can carry rocks, trees and buildings over considerable distances by following river valleys. Mount Rainier has produced many of these flows during the past several thousand years, and studies suggest that another flow could eventually reach Orting within an hour, leaving little time for evacuation.Because of that possibility, the city has developed one of the most comprehensive volcanic emergency programs in the country. Sirens are tested regularly, fire drills as well as evacuation drills are practiced in schools, and clearly marked escape routes lead residents to higher ground. The volcanic soil continues to support farming, which is one reason people continue to live here despite the long-recognized threat.
Toutle, Washington
The eruption of Mount St. Helens in 1980 changed the landscape around Toutle more dramatically than almost anywhere else in the region. Entire forests disappeared under volcanic debris, bridges were destroyed and river channels were filled with ash and sediment that was swept downstream by powerful mud flows.The community is still living with its consequences. Each year, rivers originating from Mount St. Helens carry large amounts of volcanic material to the lower valleys. To reduce the danger, engineers built the Sediment Retention Structure, a special dam designed not to store water but to trap debris before it reaches populated areas.The structure has prevented large amounts of sediment from moving further downstream, and further upgrades are planned to maintain its effectiveness. While Mount St. Helens is closely monitored, surrounding communities continue to rely on both engineering projects and scientific observations to mitigate future risks.
Mammoth Lakes, California
Mammoth Lakes is located at the edge of one of the largest active volcanic systems in North America. Beneath the ski resorts, forests and hot springs lies the Long Valley Caldera, which was formed after a massive eruption hundreds of thousands of years ago emptied a vast magma chamber.Although another eruption is not considered imminent, the volcanic system remains active. One of its most unusual threats is invisible. Carbon dioxide naturally escapes through cracks in the ground, collecting in low-lying areas where it can displace oxygen. In many parts of Mammoth Mountain, this gas has destroyed extensive areas of forest, leaving stands of dead pine trees that are still visible decades later.Monitoring stations continuously measure gas emissions, ground movements, and earthquake activity. Buildings in sensitive locations are equipped with carbon dioxide detection systems, while scientists track small changes beneath the caldera that could indicate renewed volcanic unrest.
Pahoa, Hawaii
Life around Pahoa has been shaped time and again by Kilauea, one of the world’s most active volcanoes. Rather than producing explosive eruptions, Kilauea often releases lava through long fractures in the ground, known as rift zones, from which molten rock emerges several kilometers from the summit.The eruption, which began in 2018, transformed large parts of the surrounding district. Lava buried roads, destroyed hundreds of homes and permanently altered the coastline in many places. Some neighborhoods disappeared beneath fresh volcanic rock while others narrowly escaped the surging flows.Even after the eruption ended, volcanic activity continued elsewhere on Kilauea. Residents remain familiar with hazard maps that divide the island into different lava-risk zones, and property buyers routinely consider those maps before choosing a place to live. The landscape is constantly evolving as new eruptions reshape the island from time to time.
Kagoshima, Japan
Daily life in Kagoshima moves under the watchful eye of Sakurajima, one of Japan’s most active volcanoes. Small eruptions occur so frequently that locals often consider flowing ash to be a part of normal life rather than an unusual phenomenon.Ash fall affects everything from transportation to agriculture. Weather forecasts include predictions that show where volcanic ash is expected to travel, helping residents prepare for changing conditions. Municipal authorities distribute collection bags specially designed for ash disposal, while regular street cleaning helps prevent accumulation.Schools have also adapted to the environment for a long time. During periods of increased volcanic activity, children may wear protective helmets outside due to the possibility of falling volcanic fragments. Despite these adjustments, Kagoshima continues to prosper through its busy port, tourism and agriculture, with the volcanic soil supporting crops such as tea, rice and the famous Sakurajima radish.
Naples, Italy
Few large cities live so close to active volcanic systems as Naples. Mount Vesuvius rises directly above the metropolitan area, while the vast Campi Flegrei caldera stretches beneath the city’s western districts. Together they place millions of residents within reach of future volcanic activity.Vesuvius last had a significant eruption during World War II, although its most famous event is the eruption of 79 AD that buried Pompeii and Herculaneum under ash and volcanic debris. Scientists consider another eruption at some point inevitable, even though there is no reliable way to predict when it will happen.Emergency planning has therefore become part of everyday administration. Authorities maintain plans to evacuate hundreds of thousands of residents inside designated danger zones, with transportation by road, rail and sea part of the strategy if warning signs appear. The fertile volcanic landscape continues to support vineyards and tomato farms, while Naples itself remains one of the most important ports in the Mediterranean. For many people, the benefits of living here outweigh the geological uncertainty that has endured for generations.