Bromo Volcano behind Pura Luhur Poten, the Bromo Hindu temple (Java, Indonesia).
Bromo is one of the small volcanic cones in the Tengger caldera, and it can be reached in a couple of hours walk from the village of Cemoro Lawang.
The flat and dusty Tengger caldera is called Lautan Pasir (Sea of Sand). The entire region is covered with thin volcanic ash from recent eruptions of the Bromo Volcano.
Behind the temple, on the slope of the volcano, you can see the Bromo Stairs that reach the crater edge (thin dark vertical line on this photo).
On the right, part of the Batok Volcano.
For more information about Bromo Volcano, read en.wikipedia.org/wiki/Mount_Bromo.
For more information about the temple, read java.uluwatu.org/html/national-park/pura-luhur-poten.shtml