Trekking to Bach Moc Luong Tu (officially reverted to its correct name Ky Quan San Mountain from April 7th, 2018) is a very hard adventure to the 4th highest mountain peak in Vietnam of 3,046m above sea level. The tour is for 5 days, 4 nights. While the trip can be done all year round, it is strongly recommended you do it in the dry season: November – April. It is freezing cold in late November, December, January.