A sunrise trek up Mount Batur usually starts around 2-3am, so the first hour is done almost entirely by headlamp - bring one with fresh batteries, since a phone flashlight won't last the climb.

It's genuinely cold at the summit before sunrise, even though Bali is tropical at sea level. Pack a warm layer - a fleece or light jacket - that you can peel off once the sun is up and the hike back down warms you up.

The volcanic path is loose gravel and sand in places, so closed, sturdy shoes with some grip matter more than how new or expensive they are. Trail runners or hiking shoes both work well.

Bring more water than feels necessary - at least one liter - plus a small snack for the summit, since breakfast is usually eaten while watching the sunrise rather than before setting out.

Pack a small day bag for a light jacket, water, and camera, and leave anything you don't need for the climb back at the hotel or with the driver waiting at the base.