What to see
The main sight is of course Mount Bromo. It is always bubbling, and its edges are tinged with sulphur. From Cemoro Lawang, take the path on the left fork. It leads to the Hindu temple at the foot of the mountain. From there, a steep 250-step path leads to the crater from which you can view the volcano.
Be forewarned that Mount Bromo is an active volcano. As recently as 2004, two tourists were killed when the volcano spit out molten lava, reaching as far as the Hindu temple. If the mountain appears to be acting up, stay away from it for your own safety.
Vendor selling dried flowers, mostly Javanese edelweiss, at Mount Bromo
Author: C Amalia (Creative Commons Attribution 2.0 Generic)
Mount Batok (2440m) is a dormant volcano at the northern centre of the huge caldera. It is now growing with vegetation, mostly cemara trees that can thrive in the volcanic ash.
To the north of the caldera is Mount Penanjakan (2770m). As it has a paved road, it can be reached by jeeps and even tour buses. It is crowded with tourists at around 5:00am. If you are here at a later time, you probably get the place all to yourself.