INDO LOG

the 1883 eruption of Krakatoa. It produced thick clouds of ash that created global effects.

I only have been to Vanimo, city on Papua New Guinea border, located next to Jayapura. From what I have seen, the people from Papua New Guinea frequently go to Indonesia just buy goods.

Papua is one of the least-developed province in Indonesia.
But the scary part is : it's far better developed than Papua New Guinea.

If you want to know more about the border, you can follow Agustinus Wibowo that is doing (2014) an expedition there.
There are some interesting write-ups from him, visit:

Located some 60 miles north of Timika, at Tembagapura in Irian Jaya – the most easterly of Indonesia's provinces – on the western half of the island of New Guinea, the Grasberg mine has the world's single largest known gold reserve and the second largest copper reserves.

The Grasberg Open Pit – originally a 4,100m-high mountain, which has been mined down to 3,000m.

Copper is the primary commodity, with a proven and provable reserve of 2.8 billion tonnes of 1.09%. The reserves also contains 0.98g/t gold and 3.87g/t silver.

Die heftigste je aufgezeichnete Explosion
Anfang April 1815 brach in Indonesien der Vulkan Tambora aus - das Jahr 1816 ging deshalb als das "Jahr ohne Sommer " in die Geschichte ein

Run - Pulau Run, Pulo Run, Puloroon, or Rhun is one of the smallest islands of the Banda Islands
European control of the Bandas was contested up until 1667 when, under the Treaty of Breda (1667), the English traded the small island of Run for Manhattan, giving the Dutch full control of the Banda archipelago.

Run - Pulau Run, Pulo Run, Puloroon, or Rhun

John Cage had a suite of "Three Dances for Two Prepared Pianos" that very purposefully attempts to emulate the sound of Gamelan orchestras.

There's also kulintang in the Southern Philippines, which is similar and are related by similar ancient roots.