Vietnam is not one country — it is three, and you only have time for one

The e-visa is stamped at Noi Bai airport — print it before you land and carry the fee in dong if you can. Your driver takes forty minutes into the Old Quarter, a grid of thirty-six streets each named for what it once sold: Hang Bac is still silver, Hang Ma is still paper. The hotel is a narrow tube house behind a shopfront; this is Hanoi's architecture, not a quirk.

Tonight is yours. Dinner on the street: the bun cha at Dac Kim on Hang Manh is the dish Hanoi is actually known for — grilled pork patties in broth with cold rice noodles. If you need data the moment you land, pick up a Vietnam SIM card on Viator before departure; it activates the moment you switch on the phone.

The Ho Chi Minh mausoleum opens at eight and closes by eleven; dress covers shoulders and knees, and cameras stay outside. Next is the stilt house where Ho Chi Minh chose to live rather than the Presidential Palace beside it — a useful fact about the man. The One Pillar Pagoda and the Temple of Literature, Vietnam's first university from 1070, fill the late morning.

After lunch, Hoan Kiem lake: the red Huc bridge leads to Ngoc Son temple on its island, and the streets around the lake are the easiest walking in the city. The evening belongs to Thang Long water puppet theatre on the north shore — performances at six and eight, tickets under $10, the show is forty-five minutes and worth every minute. Before you go, consider the Hanoi war history walking tour for the morning if your group has older teenagers; it covers the side of the monuments the guide boards do not.

The expressway east from Hanoi takes two and a half hours to Tuan Chau. Your junk is a wooden cruise boat — cabin, private balcony, a sundeck — and it carries you into 1,600 limestone karsts rising from green water. Sung Sot cave in the afternoon: the chambers are large enough to park an aircraft. Titov island offers a 400-step climb to a viewpoint that earns its effort. Kayaks go out at Luon cave, where you paddle under a limestone arch into a sheltered lagoon.

Dinner is seafood, served on board as the boat anchors for the night. The cabin lights go off when you are ready, and the water is flat. This is why the overnight matters: at six in the morning the karsts are still there, and the day boats have not arrived yet.

Tai chi on the sundeck at six if you are willing. Brunch is served as the junk sails back to Tuan Chau. The drive returns to Hanoi, and the afternoon IndiGo or VietJet connection covers the 750 kilometres to Da Nang in ninety minutes — less time than the Hanoi ring road at rush hour. Check in on the Han riverfront by early evening.

After dark, the Dragon Bridge on the Han River breathes fire and water at 9 pm — but only on Saturday and Sunday nights. Check what day you arrive before you plan the evening around it. Skip it if it is a weekday; the riverfront is pleasant enough without.

Ba Na Hills: the cable car climbs 5.8 kilometres in twenty minutes to a French colonial hill station at 1,400 metres. Take the first car up at eight to beat the crowd. The Golden Bridge — held by two vast stone hands — is the photograph everyone has seen; in person it is the valley below that surprises you. The French Village has crepes and coffee. Fantasy Park fills time if the children need a ride. Down by two in the afternoon.

Drive thirty minutes to Hoi An. The old town closes to traffic at dusk and opens to silk lanterns. A lantern boat on the Thu Bon river costs less than a cup of coffee back home. If you want to take something home from Hoi An, try a lantern-making class: two hours, bamboo and fabric, and you leave with a lantern you built. Good tailors here need two fittings — if you want a suit, arrive before four.

Five limestone hills between Da Nang and Hoi An, with a lift to the top if you want it. Huyen Khong cave inside the rock has a shaft of natural light through the ceiling that falls on a Buddha at the exact angle the builders intended. Allow ninety minutes for the whole site.

Lunch on My Khe beach — the strip of restaurants behind the sand will grill whatever the morning catch is. Then the transfer to Da Nang International for the evening connection home. The airport is twenty minutes from the beach, which is the right way to end a beach day. Do not buy the airport lunch; the food near the beach is a quarter of the price and twice as good.