The Toize Valley Mine is a mining cavern owned by the Lezarano Company in Tales of Symphonia. Its primary function was to excavate Exspheres from the earth and power Tethe'alla's technological advancements. It is the primary reason behind the company's rise to economic power. "Inhibitor Ore", which is needed to create Key Crests, can be found in the mine, albeit behind a large, high-tech security system.