The "largest acid barrel in the world" lures on Java

It is known as the heart of Indonesia: Java, the most important island of the world's largest island state with a good 140 million inhabitants, no other island around the world has more inhabitants. The capital Jakarta, a metropolis of ten million, is also located on the volcanic island.

Despite the crowds, there's still plenty of room for natural beauty: spectacular mountains and waterfalls, beaches lined with coconut palms, and well-stocked diving spots. A UNESCO World Heritage Site, Ujung Kulon is Indonesia's first national park, with rainforest, mangroves, coast and diverse wildlife, including the endangered Javan rhino.

Java also has a lot to offer in terms of cultural heritage. In the first millennium AD, Hinduism and Buddhism shaped the island, as evidenced to this day by Borobudur, the world's largest Buddhist temple complex, and Candi Prambanan, one of the largest Hindu temple complexes. Both are World Heritage Sites, along with the Sangiran archaeological site, where important pre-human fossils have been discovered.

In Java's cities there are also many buildings from the Dutch colonial era. Today, over 90 percent of the islanders are Muslim, practicing a moderate form of Islam. Unlike in many Muslim countries, Islam is not a state religion in Indonesia – including Java. There is freedom of religion for Christians, Hindus, Buddhists and Confucians.

It shines turquoise-blue-green, smells unbearably, is corrosive enough to decompose metal, and at 27 degrees warm like the South Seas: The Kawah Ijen crater lake is the star of the huge Ijen volcanic complex in East Java and is one of the natural wonders of Asia.

It is also called “the largest acid barrel on earth”: in 2011 it was included in the “Guinness Book of Records” as the largest overly acidic lake in the world with dimensions of around 1000 by 600 meters, a depth of up to 200 meters and a volume of 27.5 million cubic meters. It contains a number of chemicals, sulfuric and hydrochloric acid. The pH value (below 1) is lower than that of battery fluid (1).

Nevertheless, it is a popular destination for tourists, for whom hikes with gas masks are offered on site. Blue Lava night tours often get bad customer reviews (“disappointing”, “tourist trap”). On the other hand, the hiking tour at sunrise is considered worthwhile (“Absolutely breathtaking!”, “The view makes up for all the exertion”).

Smaller than tigers from the mainland, more stripes than their relatives on the island of Sumatra: Java also had its own subspecies of the big cat. The Java tiger (Panthera tigris sondaica) was present, albeit rare, until the 1980s. There are hardly any photos – this picture here was taken in 1938:

The Java tiger's habitat was destroyed for plantations, and it and its prey were poisoned. Environmentalists tried to save him, but it was too late. In 2003 the Java tiger was officially declared extinct. Supposedly there were still individual sightings afterwards – but they remained unconfirmed and without photo evidence.

If you google Java, you will not only come across the island, but also one of the most important programming languages ​​in the world, which is also called Java. There are several anecdotes about the name and the logo, which shows a stylized coffee cup. According to one, the language programmers used to go to the Java City coffee shop near their Silicon Valley office.

According to another theory, the naming was simply based on their preferred type of coffee, which in turn was named after the island of Java. In fact, particularly aromatic Arabica coffee, which is also known in Germany as Java coffee, is still grown there today.

The fossils are at least 700,000 years old and have been dubbed Java Man after where they were found. Many scientists even put their age at one million years, it could be up to 1.3 million. Remains of Homo erectus javanensis were first discovered in 1891 in East Java by Eugène Dubois.

The Dutch doctor is considered the first researcher to specifically search for the ancestors of modern humans. It was the first such find outside of Europe and (after the Neanderthals) the second worldwide.

Java, specifically Yogyakarta, is famous for batik. Don't think of hippie T-shirts: Indonesian batik has a centuries-old tradition and has been an intangible UNESCO World Heritage Site since 2009. Liquid wax is applied to fabrics by hand or with stamps. These areas are then left out when dyeing.

Different patterns and colors have special meanings, some of which were only allowed to be worn by the nobility for a long time. It was not until 1940 that the Sultan of Yogyakarta released all batik for all layers. In some shops, vacationers can try the art themselves in workshops.

The water is blood red during the flooding in Pekalongan in central Java in Indonesia. Here you already know that.

Source: WORLD / Kevin Knauer

"Can you open the window? I want to say goodbye to my beloved mountains. I want to see the jungle for the last time"

Even on his deathbed in Lembang (West Java), the German doctor and researcher Franz Wilhelm Junghuhn (1809-1864) was enchanted by the landscape of this island. "Der Humboldt von Java", the title of his biography by Renate Sternagel, fell into oblivion in Germany, but is considered by experts to be one of the greatest natural scientists of the 19th century.

After adventurous excursions, he delivered the first well-founded geological, geographical and botanical descriptions of Java and the first reliable map in his extensive, also literary appealing work. He is also considered the “father of quinine” for combating malaria: he grew cinchona trees on Java, in which the substance occurs naturally.

This article was first published in October 2021.

Bizarre, record-breaking, typical: You can find more parts of our regional geography series here.