Santa Monica or Scottsdale?

This is where the two cities are furthest apart. Santa Monica has a broad strip of pale sand along the whole town, with lifeguard towers and the pier. North of town are the quieter, more scenic coves of Malibu and Point Dume. The cool Pacific means plenty of wading and less swimming, but the beach itself is the point of a stay.

Scottsdale sits deep in the Sonoran Desert, so "the beach" means the resort pool. The nearest open water is at Saguaro and Canyon lakes, up to an hour's drive away, or on a summer tube down the Salt River.

Santa Monica eats better. Its kitchens take their cue from the Wednesday farmers market downtown, and the seasonal Californian cooking, seafood and brunch are of a high standard. Main Street, Montana Avenue and neighbouring Venice give you more casual choices.

Scottsdale's restaurants are reliable steakhouses, patio grills and sushi aimed at golfers and groups, and the strongest tables are often in Phoenix. Oddly, it is Scottsdale that has the more local food: Sonoran Mexican with green chile and huge flour tortillas. Santa Monica's cheap immigrant food is a long drive east.

Neither city is a big sightseeing destination, and their best culture is of quite different kinds. Santa Monica has the pier with its old carousel, the Route 66 end sign and the galleries of Bergamot Station. Its real draw is the Getty pair just outside town: European art at the Getty Center and antiquities at the Getty Villa.

Scottsdale's highlight is Frank Lloyd Wright's Taliesin West, along with frontier art at the Museum of the West. The Heard Museum in Phoenix and the Musical Instrument Museum add Native American heritage and world music.

Scottsdale is the place for a proper night out. Old Town's few blocks of dance clubs, rooftop lounges and patio bars fill up at weekends and in spring, with bottle service, dress codes and a party crowd until closing. Outside that district and the busy season, evenings go quiet.

Santa Monica is about a drink rather than a dance. You will find wine bars and ocean-view rooftops near the Promenade and pubs on Main Street, and the town winds down early. For clubs you have to make the long trip to Hollywood.

Both are strong outdoor bases, one on the ocean and one in the desert. In Santa Monica, chaparral canyon trails in Temescal and Topanga climb to views over the bay. Down on the shore there are surf lessons, the 35km beach path and whale-watching in winter and spring, and the mild climate lets you do all of it year-round.

Scottsdale has saguaro trails in the McDowell Sonoran Preserve and steep scrambles up Camelback. Further out are the Superstitions, horse riding and balloon flights. Summer heat confines all of it to dawn.

Santa Monica has more within a day's reach. The coast offers Malibu, Santa Barbara's mission and wine country, Laguna Beach and the ferry to Catalina. Los Angeles adds the Huntington Library, Hollywood and the downtown architecture, though traffic decides how much you fit in.

Scottsdale's best outing is north to Sedona's red rocks, with the cliff dwelling at Montezuma Castle and the mining town of Jerome on the way. Tucson and the San Xavier mission lie south. The Grand Canyon really needs an overnight stay.

Santa Monica is the easier family base. The lifeguarded beach is good for digging, the pier has a Ferris wheel, a roller coaster and a small aquarium, and the flat beach path suits family bike rides. The weather is gentle in every season, although visible homelessness downtown bothers some parents.

In Scottsdale, family stays revolve around resort lazy rivers, water slides and kids' clubs. The railroad park, OdySea Aquarium and spring training baseball are good extras. Every outing needs a car, and summer heat drives children indoors by midday.

Santa Monica is far easier without a car. Downtown, the pier and Main Street are all walkable, blue buses cover the rest of town, and the E Line light rail runs to downtown Los Angeles. You only need a car or ride-hailing for the Getty, the canyons or Hollywood.

Scottsdale is a long, car-shaped city with no light rail. A free trolley covers Old Town and the shopping areas, but you will need to drive or use ride-hailing for trailheads, resorts and the airport. At least the driving is easy, on a simple grid with light traffic.

The two are about equal for shopping but quite different in style. In Santa Monica, the Promenade is lined with chains, and the more interesting finds are the boutiques on Montana Avenue, surf shops on Main Street and design stores along Abbot Kinney in Venice.

Scottsdale has the bigger luxury mall and an Old Town gallery district of southwestern art. It also has serious dealers in Navajo and Hopi silver, turquoise and Pueblo pottery, which makes it better for something you could only buy there.

Scottsdale is the cheaper of the two, and it can become a real bargain if you go in summer, when resort rates drop sharply. Motels and Mexican food across the metro area help a modest budget all year.

Santa Monica is expensive in every season. Ocean-side hotels, restaurant bills with tax and tip, and parking all add up. Free things such as the beach, the trails and the bike path, plus cheap buses, ease the cost a little.

Neither has a major stage of its own, so it comes down to what is close by. Santa Monica offers chamber music and dance at the Broad Stage, intimate folk rooms and free summer concerts on the pier. The Hollywood Bowl and Disney Concert Hall mean a long rush-hour drive.

Scottsdale's arts centre in Old Town and the world-music concerts at the Musical Instrument Museum are its own strengths. Phoenix's symphony, opera and ballet are only about half an hour away.

Scottsdale is built for being looked after. It has a dense cluster of large resort spas, many open to day guests, with desert-themed treatments, steam rooms and outdoor pools set against mountain views. Retreats and meditation are easy to find too.

Santa Monica's version is more active and do-it-yourself. Think yoga on the sand, a run along the ocean and juice bars, with polished spas mostly limited to the beachfront hotels.