The Irch Plain is a location from The Legend of Zelda: Breath of the Wild. It is located northeast of the Royal Ancient Lab Ruins in the Hyrule Field region of Hyrule in the province of Central Hyrule.
Before the Great Calamity, Princess Zelda and Link rested under the shade of a lone tree located on the plain near a pond. Zelda was taking pictures of flowers and giving Link a brief lecture on the use of flowers that grow in Hyrule as ingredients when she spots a rare and endangered flower called a Silent Princess. She notes any current efforts to grow it domestically have failed and that it can only thrive in the wild and all she can do is hope it is strong enough to survive and prosper on its own. Afterwards Zelda spots and catches a Hot-Footed Frog much to her excitement as she wanted to test the delicacy's special properties and insists a reluctant Link to eat it raw (she is apparently unaware it must be cooked first to create a Hasty Elixir).
Many locations in Breath of the Wild are named after characters or locations from previous games. As such, Irch Plain may be named after Irch.