The Castillo de San Marcos is the oldest masonry fort in the continental United States (Castillo San Felipe del Morro in San Juan, Puerto Rico is older). Located on the western shore of Matanzas Bay in the city of St. Augustine, Florida, the fort was designed by the Spanish engineer Ignacio Daza. Construction began in 1672, 107 years after the city's founding by Spanish Admiral and conquistador Pedro Menéndez de Avilés, when Florida was part of the Spanish Empire. The fort's construction was ordered by Governor Francisco de la Guerra y de la Vega after the destructive raid of the English privateer Robert Searles in 1668. Work proceeded under the administration of Guerra's successor, Manuel de Cendoya in 1671, although the first stone was not laid until 1672.