Puellenas Canyon in Rowen, famous for being carved out 'in a single night and a day'. Puellenas is described as being a deep, steep-sided canyon that appears geologically-improbably for it's location at high altitude. It was formed when a glacial lake released, and carved out extremely quickly. Modern-day Provincial Rowen sits on the fantail of that flooding event.
The exact date of the flood is not well-established, but it happened sometime during the Mage Wars. Rowen parlance likes to claim it occured very fortuitously while a large army was marching towards Rowen from Korrinth.