Young Mars had active volcanoes near a mile-deep lake. Could life have thrived there? 

 New evidence that Mars was volcanically active around 4 billion years ago could provide researchers with more places to hunt for signs of ancient life on the Red Planet.  

https://cdn.mos.cms.futurecdn.net/CbcptgckZLDawGRm28TGSe.png

https://www.space.com/mars-volcanically-active-4-billion-years-search-for-life