Located just outside of the western Congolese city of Goma, the Nyiragongo volcano contains one of the few permanent lava lakes on the planet (Wikipedia lists but 5). Despite the precarious political situation in the DRC, a visit here isn't that difficult with a reasonably well developed visa- and permitting-process in place for visiting the country and the volcano, respectively and a fairly steep but manageable 6 hour hike from the park headquarters to the summit.
Here, I sit on the rim overlooking the circular convecting pool below me. As expected, it was a fantastic sight to behold.
Location: Nyiragongo volcano, Goma, Democratic Republic of Congo (DRC)
Lens used: 10-22mm f3.5-4.5