I have many favourite areas depending on the time of year 😂 I like hot, tropical weather until it gets so hot I have to stay inside 8am to 5pm 😆
December to end of February I like Phu Quoc Island.
March/April/May I like An Bang beach in Hoi An or Phong Nha (central rural Vietnam).
I spent June and July of 2020 travelling the north. Sapa is gorgeous, as is Cat Ba island, Ha long bay, Cao Bang & Bang gioc, Ninh Binh and Tam Coc.
August and September were still hot months. We've been in both Phong Nha and Hoi An at that time of year.
October is typhoon season in the central areas so head south. 😊