The title of this gallery may be misleading, since several sanctuaries seen in preceding galleries—Phanom Rung, Prasat Muang Tham, Phimai, and Prasat Sa Kamphaeng Yai—are also Khmer historical sites in Isaan, the broad expanse of the Khorat Plateau that forms Thailand's northeastern region. The lower Isaan area abutting today's Cambodia is particularly rich in sites containing ruins, often restored, of Khmer civilization from roughly the 9th to the 12th century—evidence of the at-one-time pervasive Khmer presence in the area.