Indonesia is situated on the Pacific Ring of Fire, making it one of the most volcanically active regions in the world. With more than 130 active volcanoes stretching from Sumatra to Papua, the country experiences frequent seismic and volcanic activity.
According to the Geological Agency of the Ministry of Energy and Mineral Resources and data from the United States Geological Survey (USGS), Indonesia accounts for roughly 13% of all active volcanoes globally. This reality places Indonesia at the forefront of global volcano monitoring and disaster preparedness.
In 2025 alone, the Volcanological Survey of Indonesia, through the MAGMA Indonesia application, recorded over 4,300 volcanic eruptions. The government, in collaboration with local and international agencies, continues to improve early warning systems and community education programmes to minimise the risks posed by major eruptions.
10 Most Dangerous Volcanoes in Indonesia
1. Mount Krakatau, the country’s most volatile volcano
Mount Krakatau remains one of Indonesia’s most well-known volcanoes due to its catastrophic eruption in August 1883. The volcano’s first eruption on 26 August generated vast clouds of volcanic ash and pyroclastic flows, followed by a massive explosion the next day. The eruption, estimated at 200 megatons, was heard thousands of kilometres away.
The 1883 eruption caused a massive tsunami and killed more than 36,000 people. Volcanic ash darkened the skies for days, affecting global weather patterns. The remnants of Krakatau, known as Anak Krakatau, continue to be monitored as an active volcano with the potential to erupt again.
2. Mount Agung, Indonesia volcano in Bali
Located in Bali, Mount Agung’s most significant eruption occurred in 1963, resulting in over 1,500 fatalities and lowering global temperatures by 0.4°C due to ash dispersion.
The eruption devastated large areas of farmland and villages in Karangasem Regency. It is located at the eastern end of the island of Bali.
When Agung erupted again in 2017 and 2018, tens of thousands of residents were evacuated. Although these eruptions were less severe, Mount Agung remains under close observation by the volcanological survey of Indonesia due to its history of unpredictable activity.
3. Mount Maninjau
Mount Maninjau, in West Sumatra, erupted approximately 52,000 years ago in one of the largest known explosive volcanic events. The eruption formed the Maninjau Caldera, spanning roughly 20 kilometres in length.
This major eruption had a significant geological impact, with deposits found up to 75 kilometres from the crater. Today, the site hosts Lake Maninjau, a scenic tourist attraction, but it serves as a reminder of Indonesia’s powerful volcanic history.
4. Mount Galunggung
Mount Galunggung in West Java has erupted several times, with the most devastating eruption occurring in 1982. This event lasted nine months and altered the surrounding landscape within a 20-kilometre radius.
The ash cloud disrupted air traffic, including an incident involving a British Airways flight. The volcano’s activity, monitored since the 1980s, highlights the importance of continuous surveillance of active volcanoes in Indonesia.
5. Mount Merapi
Mount Merapi, located in Central Java near Yogyakarta, is one of the most active volcanoes in Indonesia. It has experienced over 80 eruptions, from small to explosive eruption, since the 16th century, with the deadliest recent eruption in 2010.
That eruption killed 347 people and displaced thousands. Merapi continues to emit volcanic ash and lava domes periodically, requiring constant monitoring due to its proximity to densely populated areas.
6. Mount Rinjani
Mount Rinjani on Lombok Island experienced a significant eruption in 1994, when its Barujari cone erupted and triggered deadly lahars. The disaster caused 34 fatalities and destroyed agricultural infrastructure.
Despite its stunning beauty and popularity among trekkers, Rinjani is classified as an active volcano. The Indonesian government maintains strict regulations for climbers during periods of volcanic activity.
7. Mount Bromo
East Java’s Mount Bromo is among Indonesia’s most active volcanoes, with more than 50 eruptions since 1775. Its most notable recent eruptions occurred in 1995, 2000, 2004, and 2010.
Bromo’s eruptions often produce thick volcanic ash clouds, affecting nearby communities and disrupting flights. The PVMBG continues to observe the volcano for signs of escalating activity.
8. Mount Semeru
Mount Semeru, the tallest volcano on Java Island, remains consistently active. As of mid-2025, it had erupted over 1,800 times, making it the most active volcano in Indonesia this year.
Its most significant historical eruption occurred in 1818. Regular activity from Semeru includes ash columns and lava flows. The volcano is currently at Alert Level II, with authorities urging the public to avoid a 3-kilometre radius around the summit crater.
9. Mount Gamalama
Mount Gamalama, located on Ternate Island, has erupted more than 60 times since 1538. The most destructive eruption in 1775 obliterated the village of Soela Takomi, leaving 141 residents unaccounted for.
Its most recent eruption occurred in 2018. Given its proximity to residential areas, Gamalama remains under constant observation by Indonesian volcanological authorities.
10. Mount Kelud
Mount Kelud in East Java is one of the most explosive volcanoes in Indonesia, with over 30 recorded eruptions. Some eruptions, such as those in 1919 and 2014, caused significant damage and loss of life.
The 2014 eruption sent ash plumes over 17 kilometres high and disrupted air travel across Java and Bali. Kelud continues to pose a risk due to its highly explosive magma and unpredictable behaviour.
Active Indonesia Volcano: Mount Lewotobi Laki-Laki Erupts Again
Mount Lewotobi Laki-Laki in East Flores Regency, East Nusa Tenggara, erupted again on Monday, 7 July 2025 at 11:05 WITA, with the volcanic ash column reaching a height of 18 kilometres above the crater.
This marks the largest eruption since the volcano began showing increased activity in early 2024. The national volcanology agency stated that the ash column was grey to pitch black, ejected with thick intensity and drifting towards the north, northeast, and northwest.
Last month, dozens of flights to and from Bali were cancelled after the volcano erupted. Indonesia’s MAGMA agency also increased the volcano’s alert status after an eruption on June 18, and more than doubled an exclusion zone to a 7km radius as eruptions became more frequent.
Mount Lewotobi is known as an active volcano located in East Flores Regency, East Nusa Tenggara Province.
Uniquely, Mount Lewotobi is a twin volcano, consisting of two peaks: Mount Lewotobi Laki-Laki and Mount Lewotobi Perempuan.
Although referred to as twin mountains, the two peaks of Mount Lewotobi differ in elevation.
Living with Indonesia Volcano
Living amid volcanoes in Indonesia presents both risk and opportunity. While the threat of eruption and ash clouds remains constant, the fertile volcanic soil sustains agriculture and livelihoods. The Indonesian government, through the PVMBG and MAGMA systems, plays a vital role in monitoring and providing early warnings.
With 127 active volcanoes and a rising number of eruptions since early 2024, public education and disaster mitigation efforts are more important than ever. Residents near volcanoes must remain informed and prepared to respond swiftly when alerts are issued.
