As a youth, Peries developed an interest in rock climbing and, together with his father, climbed the Knuckles Mountain Range on several occasions. His first exploration outside Sri Lanka was on the Thai-Burmese border in 2005. He also reached the Everest Base Camp in 2010. He teamed up with Jayanthi Kuru-Utumpala in 2011 and has since worked together with her on several successful expeditions, including the summits of Adam's Peak and Island Peak in 2012, the summit of Mount Kilimanjaro in 2014, and the Mount Everest expedition of 2016. Peries has also climbed Mount Kalapattar in Nepal and Mount Kinabalu in Malaysia.