Home to one of Mars' oldest volcanoes and a nearly four-billion-year-old crust.
Tyrrhena Terra is among the oldest surfaces on Mars, dating back roughly 4 billion years. It hosts Tyrrhenus Mons, an ancient volcano built from soft, easily eroded ash — evidence of an early, explosive style of Martian volcanism.
Claim your plot here →Tyrrhena Terra reaches back almost to the birth of Mars. Its centrepiece, Tyrrhenus Mons, is one of the planet's oldest volcanoes, and unlike the towering Tharsis shields it is low, worn and gullied. That shape is a clue: it was built largely from ash and pyroclastic material, soft deposits that eroded readily where fluid lava would have stood firm.
This points to a violent, explosive early volcanism, perhaps driven by magma meeting ground ice or water. The surrounding highland is heavily cratered and deeply dissected, one of the most ancient landscapes on Mars. To stand here would be to stand on ground nearly as old as the planet itself.