sentences:  In 1959, French archaeologist Louis Malleret first described a series of 17 circular earthworks, each with an outer wall and an inner ditch.He reported this new category of prehistoric sites in the red soil region east of the Mekong in what was then part of Kampong Cham Province and in Vietnam.In 1962, Bernard Philippe Groslier carried out excavations in a circular earthwork near Memot, later called the Groslier site, and named this civilisation "Mimotien".