What is "eorpeburnan"

Eorpeburnan is the first place identified in the Burghal Hidage, a document created in the late 9th or early 10th century, that provides a list of thirty three fortified places mainly in Wessex. It details the location of fortifications designed to defend the West Saxon kingdom from the Vikings but also the relative size of burghal defences and their garrisons. Eorpeburnan is designated as having a hidage of 324, its precise location is lost in history, but scholars have suggested some possible sites.