San Antonio De Senecu
SAN ANTONIO DE SENECÚ. San Antonio de Senecú (also known as Senecú del Sur), a pueblo and mission in the El Paso area, was established in the spring of 1682 after the Pueblo Revolt in New Mexico. It was settled with Piro Indians, former residents of the pueblo of Senecú in New Mexico. The pueblo and mission were located two leagues from the site of modern Ciudad Juárez, Mexico; the Texas Highway Department has erected a marker locating the approximate site as two miles northwest of Ysleta, Texas.
Full article on the Texas State Historical Association's Handbook of Texas Online