Rizal High School (Filipino: Mataas na Paaralang Rizal) or commonly known as RHS an institution of secondary education based in Pasig, Metro Manila, Philippines, has been listed as the “largest secondary school in the world” since 1993 by the Guinness Book of World Records until 2005 when City Montessori School in Lucknow, India held the title of the world's biggest school, when it had 29,212 pupils, beating Rizal High School in Manila, Philippines, which had 19,738 pupils.