Here is a map of the Seoraksan courses in case you missed it from my other post:
|Seoraksan National Park hiking trails and course map|
Sinheungsa Temple is a few minutes walk from the Seoraksan Tourist Hotel. Biseondae is 2.3 km further away and takes around 45 minutes to get there. From Biseondae, it'll take you another 3.5 km (or 2 hours walk) to walk to Oryeon Falls in Cheonbuldong Valley. I walked as far as I could into Cheonbuldong Valley before turning around again and was probably on my feet for a good 6 hours that day.