Casimiro A. Ynares Sr. Memorial National High School (also known as CAYSMNHS) is a public high school in Taytay, Rizal. situated at the Rizal Provincial Lot Hilltop, Cabrera Road, KayTikling, Barangay Dolores, Taytay, Rizal. Its mother school is Taytay National High School. The school is now an independent public secondary school. It offers specialized curriculum specifically in English, Science, Mathematics, and ICT. The school is currently rolling out the new K-12 BEC program for students starting the school year 2012-2013. The school also has been planned to carry out the new SHS program that will start on the school year 2016-2017 but out of all 3 choices for the new program, they will be implementing the Academics area of the curriculum.HistoryCasimiro A. Ynares Sr. Memorial National High School is situated at the Rizal Provincial lot in Hilltop, Cabrera Road, Kaytikling, Taytay, Rizal. It has a total lot area of 4260 square meters which was donated by the Rizal Provincial Government through Gov. Casimiro Ynares, Jr.In 2002, the original plan was to build a three-storey building with 12 classrooms at Hapay na Mangga across the existing Hapay na Mangga Elementary School with a lot area of 3.5 hectares slope site. However, the project did not materialize due to a landslide that affected many residents in the area. Governor Rebecca Ynares offered instead a provincial lot located between the Rizal Provincial Jail and Provincial PNP Headquarters beside the DepEd Division of Rizal Office as the new site of the school.In 2004, through the initiative of People's Economic Council, the barangay officials of Barangay Dolores headed by former Barangay Captain Magtanggol E. Macabuhay Jr., and the municipal officials of Taytay through the leadership of former mayor George Ricardo R. Gacula, the construction of the four-storey building with 15 rooms started. It was turned over to DepEd Rizal with Dr. Edith A. Doblada, the School's Division Superintendent of the Division of Rizal during that time.