canals. It remained in use until the late 19th century, when it was superseded by the more systematic work of the Canal de Isabel II. A 1.3 km section remains in operation in Patones which is fed from the Canal de la Parra and Atazar Reservoir. The canal is a Grade 1 (maximum) listed site, with two ancient stone bridges classified at Grade 2 protection. It is also called a canal in Spanish. The Ermita de la Virgen de la Oliva The Hermitage, now a ruin under a preservation order, was built for a religious community in about the 12th or 13th century and was attached to the Cathedral Church of Alcala de Henares and now belongs to the successor Diocese of Complutense, based in the same town. Cueva del Reguerillo The cave of Reguerillo is the most important archaeological site in the Comunidad Madrid, in terms of both scientific interest and for recreational caving. Unfortunately, although it has been declared a monument of national interest since 1944, easy access to the cave and its close proximity to the city of Madrid made the cave a recreation center for many groups who were lacking the necessary knowledge and respect for such a site, and the cave became contaminated with trash and graffiti. Accordingly, since 2008 it has been closed to the public by the Directorate General for Heritage in the Community of Madrid, in order to allow the scientific community to perform archaeological and paleontological studies. It contains three levels of varying difficulty between 78m and 9810m depth. Detailed information can be obtained from the Spanish Wikipedia article. In 1974 a 2nd-century Celtic Druid encampment was also found nearby. Public transport Patones has three bus lines. One of them has its head at the Plaza de Castilla Interchange. The other two lines communicate Patones with other municipalities in the area Line 197: Madrid (Plaza de Castilla) -Torrelaguna / Uceda 2 services to Madrid from Monday to Friday and 3 on weekends and holidays. 2 to Uceda from Monday to Friday, 4 weekends and holidays Line 197A: Torrelaguna-Patones-Uceda 1 towards Uceda and 2 towards Torrelaguna Line 913: Torrelaguna-El Atazar 3 on weekends and holidays and 9 daily. Festivities La Candelaria (2 February) Carnival (before Lent, usually in February) Saint Joseph's Day (19 March) Saint John's Day (24 June/midsummer) References External links "De Patones De Arriba Al Pontón De La Oliva" .