Bromo isn't the highest mountain in Java — that honor goes to nearby Mount Semeru at 3,676m — but it's probably the most famous one. Bromo is in fact only one of many peaks inside the massive Tengger Caldera, but it's easily recognized as the entire top has been blown off and the crater inside constantly belches white sulphurous smoke. The inside of the caldera, aptly dubbed the Laut Pasir (Sea of Sand) is coated with fine volcanic sand and the overall effect is unsettlingly unearthly, especially when compared to the lush green valleys all around the caldera.
When timing any activities in the area, bear in mind that sunset is soon after 5 PM and sunrise is correspondingly early at around 5:30 AM. This means you'll usually need to get up by 3:30 AM or so to get there in time for dawn.
- Mount Batok (2440m) is a brown volcanic cone at the north center of the caldera. Unlike the other nearby peaks it is no longer active and actually has some vegetation growing on it, mostly the local cemara tree that somehow manages to survive even on volcanic ash.
- Mount Bromo, edges tinged with white sulphur and always bubbling, is the main sight. To reach it on foot, pick the left fork at Cemoro Lawang's solitary crossing, then head down the ramp into the caldera and then across the caldera to the Hindu temple at the foot of the mountain. From the temple a steep path of 250 steps leads to the edge of the crater and a precarious meter-wide ledge from where to gaze into the volcano.
- Mount Penanjakan (2770m), located just north of the caldera, is a mountaintop viewpoint accessible by paved road from Tosari and hence popular with jeeps and even tour buses. Most of the crowd comes to see the dawn at 5 AM, and you'll likely have the large concrete observation post to yourself if you arrive later in the day.
- Viewpoint #2, along the trail from Cemoro Lawang to Mt. Penanjakan, is an excellent way to get a stunning view of the caldera (see pictures above) without the crowds. To reach it, head west from Cemoro Lawang (past Cemero Indah) for 6 km, past farms and fields. The paved road eventually turns into a twisty mountain trail that ends with a flight of stairs on the right, and the viewpoint (with concrete shelter) is at the top. Allow 1.5 hours for the climb up at a steady pace, and bring along a torch if attempting this at night.
- From here, you can continue onto Mt. Penanjakan by following the trail upward, after which the trail merges onto the paved road to the viewpoint (total time about 60 minutes one way). If planning to return the same way, mark the spot where the trail emerges onto the road (if you pass a stone lantern on the way down, you've gone too far!), and note that descending on this section can get slippery due to loose sand and rocks.