Ysgol Maesydderwen is a small secondary school and sixth form (ages 11-18) in the Swansea valley. It serves 400 pupils from the surrounding areas of Ystradgynlais. There are some classes taught bilingually and the Welsh language is encouraged throughout the school. The school currently holds the silver eco schools award and is working towards the Green flag award; it is also recognised as a school of sanctuary. The building was built, after a fire, in 1934. In 2012 it reopened after a major rebuild; this included the leisure centre nearby.