Phoenix or Sun Valley?

Neither place has a beach, so this is about where you can swim. Phoenix has the Salt River reservoirs, Saguaro Lake and Canyon Lake, set among bare desert cliffs, and summer tubing on the river, though most swimming happens in resort pools with slides and lazy rivers.

Sun Valley has Redfish Lake under the Sawtooths, with a sandy shore and cold water even in July and August, and the heated outdoor pools in town. Phoenix is better for a long, warm afternoon in the water, Sun Valley for a bracing alpine dip.

Phoenix eats better because it has a cooking tradition of its own: carne asada, machaca, paper-thin flour tortillas and Sonoran hot dogs from family kitchens across the south and west of the city, plus serious wood-fired pizza. Driving is usually part of getting to the good places.

Ketchum does well for a small town, with après-ski grills and a few ambitious kitchens cooking trout, lamb and elk, but there is little cheap food and some places shorten their hours outside the main seasons.

Phoenix has the stronger sights, even without a historic centre. The Heard Museum is a world-class collection of Native American art, and the Musical Instrument Museum, Taliesin West, Pueblo Grande's Hohokam remains and the 1901 capitol are enough for several days, as long as you're happy to drive between them.

Sun Valley's interest is one story: the 1936 resort with the first chairlifts, the film-star photographs in the Lodge corridors and Hemingway's last years in Ketchum. A small history museum and some galleries finish it off in an afternoon.

Phoenix has real choice for a night out: the clubs and rooftop bars of Old Town Scottsdale, the student bars of Tempe's Mill Avenue and the craft beer and cocktail places around Roosevelt Row. Each is a separate destination, though, and you get home by ride-hail.

In Sun Valley a night out means après-ski in a few Ketchum saloons, wine bars and hotel lounges, with perhaps a band on a busy winter weekend. There are no clubs, and outside the peak seasons the town is quiet soon after dinner.

Both are outdoor destinations, but Sun Valley is the stronger one and it works all year. Bald Mountain gives skiers long, steep runs from the edge of town, and in summer the same slopes carry singletrack. Silver Creek and the Big Wood draw fly fishers, and the Sawtooths an hour north have alpine lakes, climbing and Salmon River rafting.

Phoenix's desert is very good in its own way: saguaro forest in the McDowell Sonoran Preserve, scrambles up Camelback, the vast South Mountain park and Sedona's red rock within reach. Its season is shorter, though, because summer heat makes hiking after mid-morning dangerous.

Phoenix gives you more places to drive to. Jerome's hillside mining streets, Prescott's saloon row, the cliff dwelling at Montezuma Castle, Sedona, and Tucson with Mission San Xavier del Bac are all within about two hours.

Around Sun Valley the country is wild rather than settled. Hailey's main street, log-cabin Stanley and Shoshone Falls about two hours south are the realistic outings, and most days out from Ketchum head into the mountains instead.

Phoenix has the attractions built for children: a zoo, an aquarium, the Arizona Science Center, a children's museum, water parks and resort pools with slides, plus spring training baseball in March. It works best from autumn to spring, with plenty of time in the car.

Sun Valley suits families who ski or hike, with a gentle beginners' hill, a good ski school and quiet streets. Nothing there is aimed at children, rainy days are hard to fill, and non-skiing teenagers may get bored.

Sun Valley is the easier place to get around without a car, at least inside the resort. Ketchum's small grid is walkable, a free bus links the town, the village and the lift bases, and a paved bike path runs down the valley. You'll still need to drive to reach trailheads, hot springs and the Sawtooths.

Phoenix is built for the car. Its light rail covers only the airport, downtown and Tempe, the buses are slow, and Scottsdale, the hiking areas and the museums lie far apart across a flat grid. Most visitors rent a car from day one.

Phoenix offers more: large malls in Scottsdale and near the Biltmore for the main brands, galleries and Western wear in Old Town, and the region's best buy, Navajo and Zuni silver and turquoise, Hopi katsina carvings and rugs from museum shops and reputable dealers.

Ketchum has only a few blocks of western art galleries, fly-fishing and ski shops and expensive boutiques aimed at second-home owners. It's fine for gear and browsing, not for a shopping trip.

Phoenix is clearly the cheaper of the two. Summer brings resort rooms down sharply, freeway chain hotels are good value all year, Sonoran Mexican food is inexpensive and the hiking is free. The main added cost is a hire car.

Sun Valley's wealthy second-home community sets the price of rooms, meals and lift access, and there is little budget lodging. Staying down the valley and coming in spring or autumn helps, but it stays an expensive trip.

Phoenix has a full season from autumn to spring: the symphony at Symphony Hall, Arizona Opera, Ballet Arizona, and touring Broadway shows at ASU Gammage, Frank Lloyd Wright's round auditorium in Tempe. Rock venues downtown and in Tempe add touring bands.

Sun Valley does one thing well. For several summer weeks a professional orchestra plays free concerts in the pavilion by the lodge while people picnic on the lawn, and skaters perform on the outdoor rink. Outside summer there is almost nothing.

Phoenix is the more polished place to rest. Large desert resorts below Camelback and in north Scottsdale have full spas, several pools, golf and treatments using sage, clay and agave, and winter brings dry warmth for long days by the pool.

Sun Valley's rest is wilder and simpler. Hotel spas and steaming outdoor pools are at their best under falling snow, and the undeveloped hot springs up the Warm Springs valley give you something Phoenix can't: a soak beside a mountain creek.