The San Felipe Castle takes its name from Philip II of Spain. It is located on a small peninsula, at the point where Lake Izabal joins the Rio Dulce river. The fortification was built in 1643 to defend the Atlantic coast of the Kingdom of Guatemala against constant incursions of English pirates and corsairs. Its towers, patios, rooms and dungeons are conserved as a sample of military architecture of the Colonial period. Because of its historical importance, the castle was declared a National Monument in 1955.