Ha Long or Nha Trang?

Ha Long's town beach at Bai Chay is imported sand on shallow, often cloudy water. The better swimming comes off a cruise boat or at small island beaches such as Ti Top, and the clean sand on Quan Lan needs an overnight trip.

Nha Trang is the opposite case. Some 6km of sand runs along the centre, a few minutes from most hotels, with the offshore island bays, the empty stretch towards Cam Ranh and Doc Let for quieter water. The catch is the autumn monsoon, when rough surf can close swimming in town, while Ha Long's off-season is its cool winter.

Both towns live on seafood picked from tanks and grilled on the spot. In Ha Long that, plus springy cha muc squid cakes and northern breakfasts such as pho and banh cuon, is most of the story. Cruise set menus and big Bai Chay restaurants make up much of the rest.

Nha Trang has more range: its own bun cha ca with fish cake and jellyfish, nem nuong pork rolls, banh can from clay moulds, and a strong drip-coffee culture on every block, which Ha Long lacks. Its weak spot is the tourist strip, where pizza and Russian menus push out the local cooking.

Neither town is a heritage destination, but Nha Trang has more to see. The Po Nagar Cham towers, still used for worship and far older than the town, give it a real historic site, backed by Long Son's white Buddha, the stone cathedral and the Yersin museum.

Ha Long's best cultural stop is the Quang Ninh Museum, a black glass building covering mining, the sea and provincial history, with the floating village of Cua Van out on the bay. Nha Trang's sights fill about a day, and Ha Long's run out sooner.

Nha Trang stays out later. The backpacker streets behind the seafront have bar crawls and loud music, beach bars put on fire shows and DJ nights on the sand, and a few clubs last into the early hours.

In Ha Long, evenings mean beer halls, karaoke and seafood in Bai Chay, and most places wind down before midnight. On a cruise, the night is a drink on the sundeck and squid fishing. Neither town is worth choosing for its nightlife, but only Nha Trang offers a proper late night.

This is Ha Long's great strength. Close to two thousand forested limestone towers rise from the bay, with caves such as Thien Cung, kayaks slipping into enclosed lagoons, and Lan Ha, Bai Tu Long and Cat Ba's national park adding trails and rock climbing. Few coastlines anywhere look like it.

Nha Trang's ring of green islands is attractive rather than extraordinary, but it has something Ha Long lacks underwater: the protected reefs around Hon Mun, among Vietnam's favourite snorkelling and diving grounds. On land it adds the Ba Ho waterfalls and the forested hills of Hon Ba.

Ha Long has the better outings within an hour. Yen Tu is the holy mountain of Truc Lam Zen, with pagodas climbing through old forest. Hai Phong is a port city with French colonial streets, and the Bach Dang battlefield is nearby. Boats also reach Cat Ba and the Bai Tu Long islands.

From Nha Trang, the main heritage trip is about two hours south, to the Cham towers of Po Klong Garai and the pottery and weaving villages near Phan Rang. Dalat needs a night away, so most visitors stay put.

Nha Trang has the edge for families, mainly because of the beach: a long, gentle stretch of sand right in town. It also has the Hon Tre island park, with rides, a water park and an aquarium, the turtles at the Oceanographic Institute, and mud baths that children enjoy.

Ha Long's appeal is adventure: caves, kayaks and swimming off a deck, with Sun World's cable car and water park in Bai Chay. Overnight cruises suit older children better than toddlers. In both towns, scooter traffic and broken pavements are hard work with a buggy.

Nha Trang is simpler to manage. Hotels, restaurants and the beach sit in one walkable strip along the promenade, and ride-hailing or a hired scooter covers the rest. The one awkward leg is Cam Ranh airport, about 35km south.

Ha Long is split into Bai Chay and Hon Gai across a long bridge. Beyond the waterfront, distances are long and pavements patchy, so taxis do most of the work. Cruise transfers from Tuan Chau are usually included, and arriving means a road journey from Hanoi.

Shopping is modest in both towns and built around markets and products of the sea. Nha Trang has a little more: the round Cho Dam market hall with coffee, cashews and fabric, a night market with lacquerware, and agarwood and bird's nest as regional specialities.

Ha Long offers pearl showrooms, Bai Chay's night market of trinkets, and Hon Gai market's fish sauce and dried squid, which remains the most honest souvenir from either town.

Both towns are very cheap on land, with inexpensive hotels, street food and ride-hailing. The difference is where the money goes. In Ha Long it is the overnight cruise, the biggest cost of most visits, with boats ranging from basic to luxurious. In Nha Trang it is the beachfront resorts, the island amusement park and dive trips. In both, agree on the weight and price of your seafood before it is cooked.

Neither town has a theatre, a concert hall or a regular programme. In Ha Long it comes down to staged shows in the Bai Chay entertainment complex and folk singing on some cruise boats. Nha Trang has cover bands in beach bars and occasional Cham music or folk dance, sometimes at the temple sites.

Nha Trang has a signature treatment that Ha Long cannot match in town: soaking in warm mineral mud near the Thap Ba hot springs, then rinsing off in hot spring pools. It also has massage on almost every street, resort spas on the quieter bays and slow mornings on the beach.

Ha Long's calm is out on the water, with tai chi on the sundeck at dawn and nights anchored in a sheltered cove, while the town on land is loud. Its best bathing is the Quang Hanh onsen resort, about forty minutes east.