Safety / Health

Java is essentially malaria-free. Unlike eastern Indonesia, the main Java tourist areas don't require prophylaxis — dengue is the real mosquito risk, so pack repellent and cover up at dusk.

Bring real layers for the volcanoes. Bromo and Ijen summits hit 5–10°C pre-dawn — a proper jacket, gloves and hat make or break the sunrise wait.

Take the Ijen gas mask seriously. Sulfur fumes are genuinely toxic; rent a proper mask, wear glasses not contacts, and back out if the gas thickens.

Check volcano status before every mountain. Semeru especially is highly active and access closes during eruptions/lahars — confirm on Magma Indonesia the day before.

Waterfall descents are no joke. Tumpak Sewu, Coban Sriti and Kapas Biru involve slippery ladders and river crossings — skip them after rain and consider a local guide.

Watch for motion sickness. The mountain switchbacks to Nepal van Java, Bromo and the Ijen base camp are relentless — medicate if you're prone.