According to some historians Las Rozas de Madrid could have been a Roman mansion or staging-post called Miacum, from which the name Madrid may have derived. This is somewhat speculative, although there is evidence of occupation locally in about the 3rd century of the Common Era when the Roman Empire was active in Spain. Las Rozas is located on the Roman Military Route between Segovia and Titulcia and eventually to Emerita Augusta, and is adjacent to the Rio Guadarrama, which provided plentiful fresh water all year round. The modern name means 'the clearings' which may have related to military activity, as the agricultural value if the area is low, and the traditional economic activity seems to have been sheep rearing. The first document that refers to Las Rozas itself dates from 1376, although it would appear that the town existed earlier than that. The town of "Las Rozas" appears in Volume V of the "Relaciones Historico-Geografico-Estadisticas" ("Historical, Geographical, and Statistical List") of the towns of Spain that was written during the reign of Felipe II and that is now kept in the library at the El Escorial Monastery. Middle Ages The Pasture of Holy María of the Retamar appears mentioned in a letter dated to November 18, 1303 in a lawsuit between Madrid and Segovia also relating to settlements at Galapagar, Torrelodones and Colmenarejo. The legend says that the Virgin of the Retamar appeared there, but the contemporary carved image is not that today appears in a scallop niche in the Church of San Miguel and which is used for the processions that carry the Virgin to the new hermitage church that was built in the 1990s, which is a little nearer the town, next to Dehesa de Navalcarbón (the original, as 'pasture' suggests was near the river. Industrial Revolution During the reign of Carlos III an ambitious project was conceived to create a navigable canal sourced by the river Guadarrama which would link Madrid to the Atlantic Ocean. Finally in 1875 a French Engineer, Charles Lemur started work. Only 27 km was actually built (the dam of El Gasco, the regulating reservoir) when a great storm destroyed the project. A short section has been restored in the Dehesa de Navalcarbon nature park. In a map of the year 1755, the name (Las Matas) appears, that was populated by laborers that built the highway to Segovia (now part of the