Corral - Random House Unabridged Dictionary: "Corral: a circular enclosure formed by wagons during an encampment, as by covered wagons crossing the North American plains in the 19th century, for defense against attack"

laager - A laager, lager, leaguer or laer (Afrikaans, from Dutch leger (camp or army); Afrikaans pronunciation: [ˈlaːɡər] or [ˈliɡər]). The word is South African in origin, and originally referred to a formation used by travelers whereby they would draw wagons into a circle and place cattle and horses on the inside to protect them from raiders or nocturnal animals. In 19th century America, the same approach was used by pioneers who would "circle the wagons" in case of Indian attack