Today's Image of Mars is of a crater filled in by lava flows from the volcano Arsia Mons, one of the northern most Tharsis volcanoes.
What's amazing about this crater is the fact that the rim remains almost entirely intact. Oftentimes all evidence of an impact will be erased by a lava flow, but not in this case. The lava flows surrounded this crater and eventually broke through the crater rim, filling it to the same level as the surrounding terrain, but the rim is still distinct.
Clicking this image will take you to the original captioned image from Mars Odyssey Orbiter's THEMIS.