Regellia is an average-sized planet in the Karideph system, located very close to the system's sun. It has a very harsh environment caused by multiple volcanic eruptions every week that spew toxic gases into the atmosphere. Although the core of the planet is not very hot, its proximity to the sun means that minor gravitational fluxes cause the planet's crust to shift. This ruptures the surface and allows for the magma to escape the mantle. Over the course of the planet's life, a massive lava sea has formed and now covers around a third of the planet's surface. The rest of Durthang is rock, with a few deserts composed of the worn-down remains of volcanoes. Terrible storms wrack the entire planet periodically, scouring the surface of anything that is not protected, making life away from the cities very hazardous to those few prospectors aiming to find a rich deposit of rare materials.

Even though the planet's surface is inhospitable, there is a small tourist trade for those few people who come to see the great lava sea. It is one of the wonders of the galaxy and inspires awe in all that see it. One can only imagine the raw essence of the planet upon viewing such a vista, and there are many cults that base their beliefs around this phenomenon.