Ho Chi Minh City or Nha Trang?

This is the biggest gap between the two. Nha Trang's 6km of sand runs the length of the town, with a palm-lined promenade behind it and calm morning water through spring and summer. Boats go out to quieter island bays, and Doc Let and the long sands towards Cam Ranh are within reach.

Ho Chi Minh City is a river city. Its nearest coast is the muddy mangrove shore of Can Gio, and Vung Tau, two hours away, has cloudy water and weekend crowds. Anyone who wants to swim there will use a hotel pool or plan a separate beach leg, often to Nha Trang itself.

Both run on plastic stools and drip coffee, but Ho Chi Minh City has far more range. It has broken rice, banh xeo, snail streets after dark and the Chinese-Vietnamese cooking of Cholon, with modern Vietnamese, French and international restaurants around Thao Dien above them.

Nha Trang is better for seafood grilled at the table and its own dishes, such as bun cha ca with jellyfish and nem nuong pork rolls. Beyond these it thins out quickly, with fine dining mostly in resort hotels and tourist menus that drift towards pizza.

Ho Chi Minh City has more to see, most of it twentieth-century history. There is the War Remnants Museum, the Reunification Palace and the French landmarks around Dong Khoi, plus Cholon's incense-filled assembly halls. That is two or three full days.

Nha Trang's best sight is actually older. The Cham towers of Po Nagar predate anything colonial in Saigon and are still used for worship. With Long Son Pagoda and the Yersin museum added, though, the town takes about a day to see.

Ho Chi Minh City has both more nightlife and more variety. It runs from beer at pavement tables and the neon of Bui Vien to rooftop bars over the skyline, cocktail bars up old stairwells and clubs full of young locals.

Nha Trang's evenings are resort-style. There are bar crawls in the backpacker blocks, fire shows and DJ nights on the sand, and a few late clubs. Locals spend the evening over beer and grilled seafood at long tables. It's fun for a few nights, but you wouldn't choose the town for it.

Nha Trang has real scenery right by the town: steep green islands in the bay, mountains behind, and the protected reef at Hon Mun for snorkelling and diving. The Ba Ho waterfalls and the forested hills of Hon Ba make good half-day outings.

Ho Chi Minh City is flat and built up, with a few parks for dawn exercise. Its nature means the Can Gio mangroves with their macaques, or the canals of the Mekong Delta by boat or bicycle. It has no hills and no clear water.

Ho Chi Minh City is the better base for outings. The Cu Chi tunnels and the Cao Dai temple at Tay Ninh make a full day, the Mekong towns of My Tho and Ben Tre are two hours south, and Vung Tau covers the seaside.

From Nha Trang, the one strong heritage trip is Phan Rang, for the towers of Po Klong Garai and the Cham pottery villages. Dalat and the older ports up the coast need an overnight stay, so most visitors make the bay itself their outing.

Children are warmly welcomed in both, but Nha Trang gives them more to do. There is the sandy beach, the Hon Tre island park with rides, a water park and an aquarium, turtles at the Oceanographic Institute and the mud-bath parks.

Ho Chi Minh City has the old zoo, Dam Sen and the eccentric Suoi Tien. Even so, families there mostly fall back on the hotel pool and short car rides, because the streets are hard going with a pushchair.

Getting around is roughly equal, with ride-hailing cars and motorbike taxis doing most of the work in both. Ho Chi Minh City has more choice: a walkable colonial core, one clean metro line from Ben Thanh and a river bus. It is also a huge city with hard pavements and a risk of bags being snatched from passing motorbikes.

Nha Trang is simpler. Most of what a visitor needs lies along the seafront strip, which is easy to walk, and the islands are reached by boat. The airport at Cam Ranh is 35km away, though, so arrivals need a car or shuttle.

Ho Chi Minh City has much more to buy. Ben Thanh is good for haggling over coffee and silk, Binh Tay in Cholon is a working wholesale market, and tailors make suits and ao dai within days. There is lacquerware and Song Be ceramics, malls with international labels and small boutiques in Thao Dien.

Nha Trang has Cho Dam's dried squid and cashews, a beachside night market and local pearls and agarwood. It has no fashion streets or design shops.

Both are very cheap, and street food, coffee and motorbike taxis cost little in either. What differs is where the money goes. Ho Chi Minh City's pricier side is the business-capital world of international hotels, rooftop bars and imported wine. In Nha Trang it is the beach extras: resort hotels, the island amusement park, dive and boat trips, and seafood priced by weight, which is worth checking before ordering.

Ho Chi Minh City at least has a stage. The French-built Opera House hosts ballet, the symphony and acrobatic shows about southern village life, and there is water puppetry, cai luong opera and small jazz rooms. That is enough for an evening or two.

Nha Trang has very little: cover bands in beach bars and the occasional folk or Cham music show for tourists, with no regular theatre or concert season.

The two are close here, but the kind of rest differs. Ho Chi Minh City's ritual is the long reclining hair wash with scalp and face massage, plus cheap foot massage at the end of a hot day. Calm outside the treatment room has to be found in temple courtyards or in Thao Dien.

Nha Trang has warm mineral mud baths and hot spring pools near Thap Ba, and slow mornings on the beach. Its quieter bays outside the high-rise centre offer real peace, which the big city cannot.