The margin of Olympus Mons consists of a cliff-like edge where elevation changes very quickly over a very small width. This edge is called Olympus Rupes. This VIS image shows part of that edge and the lava flows that spilled over the edge to flood the surrounding plains.
Orbit Number: 65335 Latitude: 16.0811 Longitude: 221.373 Instrument: VIS Captured: 2016-09-05 12:58
http://photojournal.jpl.nasa.gov/catalog/PIA21155