Honolulu or San Juan?

Both cities have warm water and beaches inside the city, but Honolulu's are easier to use and more varied. Waikiki's reef-sheltered water suits beginner surfers and gentle swimmers, Hanauma Bay is a natural snorkelling bowl, and the soft white sand of Kailua and Lanikai is under an hour away. In summer, the North Shore calms down enough for swimming.

San Juan's sea is a few degrees warmer, and Isla Verde and the bay at Escambrón are well protected. Still, more of its city coastline, including parts of Condado and the shore towards Piñones, has strong currents, so you often need a lifeguarded balneario. Luquillo is the classic escape.

The two are close for eating well, and in both the casual places beat the formal ones. The difference is in the cooking itself. Honolulu's food mixes what Hawaiian, Japanese, Chinese, Korean, Filipino and Portuguese families brought: poke sold by weight at fish counters, plate lunch, Portuguese malasadas, and excellent ramen and izakaya. Kaimuki and Chinatown are where locals eat.

San Juan cooks Puerto Rican food, heavier and built on plantain and pork, with mofongo, alcapurrias and the weekend roast-pork stalls of Guavate. Both have island coffee worth trying: Kona and other Hawaiian coffees in Honolulu, and coffee from the mountains in San Juan's cafés. San Juan also has rum and the piña colada, which it claims as a local invention.

San Juan has the stronger set of sights, and they are all in one place. Old San Juan's walled grid of pastel houses, the forts of El Morro and San Cristóbal, and the cathedral with Ponce de León's tomb make a UNESCO-listed old town you can walk round in a day.

Honolulu's history is more spread out and more about the twentieth century: Iolani Palace and the Bishop Museum for the Hawaiian kingdom, and the Arizona Memorial and the Missouri at Pearl Harbor for the war. Both make a fine few days, but only San Juan offers centuries-old streets to wander.

This is one of the biggest gaps between the two. San Juan really goes out: crowds drink in the street at La Placita from Thursday to Saturday, and the bars around Calle San Sebastián switch between salsa and reggaeton until late.

Honolulu's evenings are about a mai tai at sunset, then a cocktail or craft beer in Chinatown or Kakaako, and an early night before a morning in the water. It suits couples well, but if you want to dance, go to San Juan.

Honolulu has the landscape right on its doorstep. The Diamond Head crater, the Manoa Falls rainforest and the steep Koolau ridges are all close to Waikiki, and turtles, surf and passing humpbacks are in the water in front of the city.

San Juan has fine places too, but you have to drive to them. El Yunque's cloud-wrapped rainforest is under an hour away, and the bioluminescent lagoon near Fajardo is something Oahu cannot offer. In town, though, the open space is limited to the lawns around El Morro and the Piñones mangroves.

San Juan has more to see beyond the city. Ponce, over the mountains, has a colonial plaza and a major art museum, Loíza is the home of bomba and Afro-Puerto Rican culture, and a short ferry takes you to the rum distillery at Cataño. Culebra and Vieques make an excellent overnight trip.

On Oahu, the choices are smaller: the surf town of Haleiwa, Kailua, the Polynesian Cultural Center and a loop around the island. The other Hawaiian islands need a flight and really deserve a few nights each.

Honolulu is clearly better set up for children. It has a zoo, an aquarium, Sea Life Park, a water park, calm lagoons at Ko Olina, and surf lessons and the Pearl Harbor ships for older children.

San Juan is easy to manage, with familiar US standards and calm beaches at Escambrón and Luquillo, and children love El Morro's tunnels and the kite lawn outside it. Beyond that, little is built for families, and you have to plan around the steep cobbles and the midday heat.

Honolulu is the easier city to get around without a car. Waikiki is flat enough to walk from end to end, and TheBus reaches Pearl Harbor, Chinatown and even the North Shore, so most visitors only hire a car for a day or two.

In San Juan, the old town is walkable but hilly, and its single rail line misses both the old town and the beaches. Taxis and ride-hailing link Condado and Isla Verde, and you will need a car or a tour for El Yunque, Luquillo or Ponce.

Honolulu has more for shoppers. The luxury houses along Kalakaua Avenue and the vast open-air Ala Moana Center are destinations in their own right, and aloha shirts, koa bowls and ukuleles make souvenirs worth carrying home.

San Juan has one huge mall in Plaza Las Américas and a short run of designer shops on Ashford Avenue. Its best buys are crafts from Old San Juan: carved santos, vejigante masks, guayaberas and cigars.

Neither is cheap, but San Juan is noticeably easier on the budget. Its costs are roughly those of a mainland US city, and kiosks, roadside stalls and the forts' modest entry keep the days affordable.

Honolulu is one of the most expensive places you could choose, with high hotel rooms, resort fees, car hire and restaurant bills. Plate lunches, poke counters, the bus and free hikes and beaches help, but the overall bill is still higher.

San Juan has more live performance. Salsa bands play to full dance floors, open bomba sessions let visitors join in, and the Centro de Bellas Artes and the Casals Festival give it a proper classical and theatre calendar.

Honolulu's strength is narrower but distinctive: slack-key guitar, falsetto singing and hula, from the free shows at Kuhio Beach to the chanted ancient form. Beyond that, the Hawaii Theatre and short symphony and opera seasons are all there is.

Neither city has a bathing tradition, so in both, wellness means resort spas. Honolulu is more restful overall. It has its own lomilomi massage and dawn yoga on the sand, and Kahala, Ko Olina and the windward side give you real quiet close by.

San Juan is louder. Weekend music and traffic carry through the streets, so for real calm you either stay inside a Condado or Isla Verde resort or leave for the countryside or the small islands.