Given the question: Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Cantref Reservoir -  Cantref Reservoir is the middle of the three reservoirs in the Taff Fawr valley in South Wales. It is owned by Welsh Water. It is located in the Brecon Beacons National Park mostly in the Powys unitary authority area and within the historic county boundaries of Breconshire. Part of the south west corner is in the Rhondda Cynon Taff unitary authority area.A public footpath crosses the dam and links with the Taff Trail and the Navvies Line paths.
The answer is:
Natural Place