Reiden Patera is a volcanic feature on Jupiter's moon Io. It was first detected by the Galileo SSI Team during the spacecraft Galileo's first orbit around Jupiter, initially detected as a hotspot. It was once thought that the activity there had stopped or waned below the limits of the spacecraft's Solid State Imager or Near-Infrared Mapping Spectrometer. However, it was noticed in 2002 that Reiden Patera has darkened considerably since the 24th orbit of Galileo. (wikipedia entry)
A patera is an irregular crater, or a complex one with scalloped edges. Usually the dish-shaped depression atop a volcano. On Io they are named after words for fire, sun or thunder; volcano gods, heroes, goddesses or mythical blacksmiths.
Image Source. Marker locations are approximate and may not always appear to align with image on map.