That one in Indonesia is also purported to be a sacred place of healing for the locals. Most of it is covered up and forests are all around it. It could be massive but hidden. This is the music the locals still play: https://m.facebook.com/abumarlomaster/videos/the-karinding-is-sundanese-traditional-musical-instrument-from-west-java-and-ban/10157986280857896/?_se_imp=0BufPbAtTR7RkTxNL I think it may have been from back when the civilization that built that pyramid existed.