The door
Door: Giap Bat long-distance station or hotel car are common; rail/bus combos follow that day’s timetable. One-way often ~2–3 hours — out-and-back is a full day. Inland Halong (Tam Coc / Ninh Binh area) replaces one city day; it is not poured into Hanoi’s permanent place graph.
Return and conflicts
Same return-night ban on Beer Street and late nights before a mausoleum morning. If a 3-day plan already has Halong, keep Ninh Binh for another trip — do not stack two long-distance days then force Old Quarter night lanes. Save energy for a light Literature or Hoan Kiem day after.