The Plains of Eidolon is an expansive, open Landscape located on Earth, measuring nearly 5 square kilometers (2.25km x 2.25km) in area. This vast space was the site of an Old War battle between the Orokin and the Sentients, with the latter's massive skeletal remains scattered throughout the land, and the Grineer have set up various outposts to study the ruins. This Landscape will be introduced in the eponymous Plains of Eidolon update.