The Ta Chi Nhu Mountain (aka Mount Phu
Song Sung) in Tram Tau District of Yen Bai Province, which is 2,979m
above sea level, is the 6th highest mountain peak in Vietnam.
The best time to climb Ta Chi Nhu is
from November to early April. If you want to take photos of an ocean of
clouds at the mountain peak, then you may want to take the trip from
November through the first half of March. It is freezing cold from late
November through early February.