Please answer the following 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. Phetchabun Mountains - The Phetchabun mountains (Thai: Thio Khao Phetchabun IPA: [tiw kaw pet.ta.bun]) are a mountain massif in Phetchabun Phitsanulok Loei and Chaiyaphum Provinces Thailand.
A:
Natural Place