The Spanish military engineer Antonio de Gaver oversaw the construction of castles, forts, and other military installations in Spain and on the Spanish-Portuguese border beginning as early as 1719, and he was a prolific cartographer and surveyor. The Gaver manuscript ("Relacion general...de las plazes de Oran, Mazalquivir su importancia, actual estado de defensa de ambas, sus castillos, fuertes, quarteles, y de mas edificios militares con una brebe noticia de su conquista, perdida, recuperacion vecindario, consumos, guarnicion, clero, ministerio, govierno militar, politico, y de mas circunstancias notables") is a thorough study of military installations in several fortified towns in North Africa, including Oran, Mazalquivir, Ceuta, and Melilla, with notes on their population, government, and history, as well as a more extensive a history of Oran during the years of spanish domination, 1505-1541. Bound neatly in vellum, the volumes contain other material of historical interest, including a brief description of the kingdom of Tremecen in North Africa, a synopsis of the Franco-Spanish treaty of 1761, and two poems by Don Sebastian Fernandez de Medrano. The volume is accompanied by a manuscript map, Plano del puerto y plaza de Oran y Castillo Mazalquivir.