Before modern public schools, Korean public schools were called Hyanggyo (향교). The Hyanggyo were first started in the Goryeo Period (918-1392) and ended sometime in the Joseon Period (1392-1910). While the Hyanggyo fell into disuse, the Seowon (서원) faired much better than the Hyanggyo. The Seowons were privately run schools for the sons of the elite. Here is a previous article about it: All over Korea you can still see various Hyanggyo, some of which are still being used for educational purposes.
The Yangyang Hyanggyo (양양 향교) has been dubbed as the 105th treasure of Gangwon Province (강원도). If you watch the video you’ll see a gate in front of the Hyanggyo. This gate was called the Hongsalmun (홍살문). The hongsalmun indicated that the person was about to enter an important site. Towards the top center of the hongsalmun is the image of the taeguk (태극), which can still be seen on the Korean flag. The taeguk is a circle with a ying and yang symbol.
In the old days the way to move up in society was to get a good education. The Pyungchang Hyanggyo (평창 향교) is one good example of a public school that mostly the sons of the elite attended. Sometimes the illegitimate sons of powerful men attended these schools through political connections. In some ways the Hyanggyo were cram schools where students were taught subjects that would be in the national civil service examination. These examinations were called Gwageo (과거).
The Goheung Hyanggyo (고흥 향교) is still in use today. The lecture hall of Goheung Hyanggyo is still used to teach interested participants about Confucianism and the subjects that were tested on the Gwageo. There is a ritual hall at Goheung Hyanggyo called the Myeongnyundang (명년당). Every month students make ritual offerings in the ritual hall called the Daeseongjeon (대성전). Keeping up with these rituals is a way for the students to keep Korea’s past alive and relevant.