There are many Buddhist temples with the usage of 불교의 만자, but I can't find any informaiton about where the oldest symbol is. The book by Thomas Wilson addresses the history (pre-history) but does not specifically address Korean history of this.
1 Answer
Do you want temples or literature?
According to this page, there are many swastikas in Goryeo Dynasty Buddhist paintings.
http://www.ibulgyo.com/news/articleView.html?idxno=66000
And this painting is from the 14th century. https://ko.wikipedia.org/wiki/%EC%95%84%EB%AF%B8%ED%83%80%EC%82%BC%EC%A1%B4%EB%8F%84_(%EA%B5%AD%EB%B3%B4_%EC%A0%9C218%ED%98%B8)
