INDONESIA – Minh Phung, a traveler from Da Lat, spent 5 days in July trekking in Java, a region known for its thousand-stream waterfall, the world’s largest acidic lake, and active volcanoes.
Java is the fourth-largest island in the Indonesian archipelago and the twelfth largest in the world. Located on the Pacific Ring of Fire, Java was formed from volcanic eruptions tens of thousands of years ago. The island is home to over 100 volcanoes, with around 40 of them still active.
During his 5-day journey from July 7th to July 12th, Tran Minh Phung, a 32-year-old from Da Lat, embarked on a trekking adventure along the Ijen – Tumpak – Bromo route to witness two famous volcanoes: Bromo and Ijen, and admire the Tumpak thousand-stream waterfall. Bromo is one of the five most beautiful active volcanoes in Asia, and Ijen is the world’s largest acidic lake. Phung dedicated one day to explore each of these destinations.
The first trekking destination was Kawah Ijen, located in the Ijen volcano complex, nestled between the Bondowoso and Banyuwangi plateaus in eastern Java. Situated at an elevation of 2,300 meters above sea level, it is the world’s largest acidic lake with a capacity of 36 million cubic meters. The lake’s surface is consistently covered with dense white smoke and carries a strong scent of hydrogen sulfide.
At 4 in the morning, from the Ijen base camp, groups of people holding flashlights and wearing gas masks lined up to ascend the mountain. The steep ascent to the mouth of the Ijen volcano involves slopes with angles of 45-60 degrees. Trekking for 4 kilometers in pouring rain, Phung and his group decided to brave the elements wearing rain gear.
Upon reaching the summit after the rain had ceased, a magnificent pink and purple landscape unfolded before their eyes. “The pink and purple hues stretched across the sky, contrasting with the emerald blue lake and the cold gray mountains and cliffs. In the distance, mist and white smoke rising from the heart of the lake created a dazzling and mystical scenery,” Phung said.
Following sunrise, the group descended 300 meters from the volcano’s mouth into the crater of Mount Ijen. At the foot of the acidic lake lay a pure sulfur deposit with a vibrant yellow color, resembling fresh turmeric. Irul Nurulah, a local guide, explained that locals come here to collect and sell sulfur.
Ijen is one of the rare places on Earth where you can observe blue flames emitting from sulfuric fumaroles at night, typically between 3 and 4 a.m. This phenomenon results from the combustion of sulfur combining with oxygen in the air. However, due to the rain, Phung’s group arrived later and missed witnessing this fascinating natural phenomenon.
Pink-purple sunrise over Mount Ijen, below is the world's largest acidic lake.
In the afternoon of the same day, the group traveled to a village near Tumpak waterfall for convenience on the following day’s journey. Upon arrival, they were informed that the area had recently experienced continuous rainfall, making trekking potentially hazardous. Though it seemed like the trek would be disrupted, the next morning brought clear skies. The group set off at 7 a.m. and arrived at the waterfall’s summit by 8 a.m.
Tumpak Sewu, also known as the thousand-stream waterfall, is formed by water cascading from the top into multiple smaller streams. “The waterfall resembles a delicate piece of silk fabric with parallel white threads. It can be considered one of the most beautiful waterfalls I have ever seen,” Phung remarked. Due to the recent heavy rain, the waterfall had a strong flow, making it impossible to descend below it and only viewable from above.
Departing from Tumpak waterfall, the next destination was the village of Cemoro Lawang, situated near Mount Bromo on the Tengger Plateau in eastern Java. This plateau was formed by volcanic ash from the eruption of Mount Tengger approximately 45,000 years ago.
Mount Bromo, along with Kursi, Watangan, and Widodare, constitutes a group of small volcanoes within the Tengger volcanic crater, which spans 16 kilometers and is approximately 820,000 years old. The surrounding landscape consists of black sand and gray volcanic ash. “Looking at the massive Tengger volcano from afar, with black sand below, and the sun and wind above, the scene reminded me of a scene from a time-travel movie,” Phung said.
Waking up at 2 a.m. to prepare for the mountain climb, Phung was surprised to see a large number of people arriving early to witness the sunrise, with European tourists being the most prominent. To reach the sunrise viewpoint at Bromo, visitors take a jeep to the mountain’s base and then trek for about 500 meters. Similar to Ijen, the sunrise scene at Bromo features shades of purple and pink. Since the volcano is still active, it continuously emits smoke. A thick column of white smoke rises high and turns pink when the sunlight hits it.
The path from the sunrise viewpoint to the mouth of the Bromo volcano crosses a sandy desert with “ridges and valleys reminiscent of comic book landscapes,” Phung shared. The massive dinosaur-like ridges, featuring dozens of serrated ridges formed by volcanic eruptions, remain intact. The route, with towering cliffs on one side, resembles Vietnam’s Mã Pì Lèng Pass.
After walking an additional 3 kilometers, Phung arrived at the mouth of Bromo volcano, where carbon dioxide gas from the Earth’s interior is expelled into the atmosphere. “The moment I stood at the mouth of Mount Bromo was one of the most beautiful moments of my life because it was the first time I witnessed an active volcano in real life,” he said. From Bromo, visitors can clearly see Semeru, the highest active volcano in Java.
Sunrise over Mount Bromo seen from a distance.
The booming sounds of the hot rocks bursting reminded travelers that this volcano was still active, with streams of molten sulfur bubbling deep within the Earth. Bromo’s most recent eruption in early 2011 resulted in two fatalities and the closure of many airports in the region.
In July, the island experienced frequent rainfall, with an average temperature of about 12-14°C. Travelers planning a visit should bring warm clothing and prepare physically for the challenging trekking, which involves continuous movement over three days.
Phung spent 660 USD on the trip, including 162 USD for the tour, 250 USD for round-trip airfare, 83 USD for accommodation, and the remainder for food and other expenses.
The journey brought “many firsts” to Phung’s life. Additionally, there were several plans that he couldn’t fulfill, such as witnessing the glowing sulfur streams at night or descending below the base of the thousand-stream waterfall. “There are many regrets from this trip, perhaps the reason why I have an appointment with this trek again,” Phung said.
