Denver or Phoenix?

Neither city is anywhere near the sea, so swimming in both means freshwater or pools. Denver's options are the sandy reservoir beaches at Cherry Creek and Chatfield on the city's edge, while its mountain lakes stay cold even in high summer.

Phoenix swaps those for the Salt River reservoirs among bare desert cliffs, plus tubing down the river. The real difference is the resort pool, with lazy rivers and slides, which is where a Phoenix summer is actually spent.

The two eat about equally well, but around a different centre. Denver's identity is beer, with taprooms in RiNo's warehouses, plus green chile smothered over burritos and Vietnamese and Mexican cooking along Federal Boulevard.

Phoenix leans into the Sonoran borderlands: carne asada, paper-thin flour tortillas and bacon-wrapped hot dogs from evening carts, plus a strong name for wood-fired pizza. Its good places are more spread out, so a meal often starts with a drive.

Both are young Western cities, and both have notable Native American collections, at the Denver Art Museum and at Phoenix's Heard Museum. The difference is how you see them. Denver's main sights sit together around Civic Center Park, and the brick warehouses of LoDo and Larimer Square give it an old commercial quarter to walk.

Phoenix has no historic centre to wander. In return it has the Musical Instrument Museum and Frank Lloyd Wright's Taliesin West, though each one is a separate drive.

Evenings out are much the same in scale, but different in style. Denver is a city of bars and breweries spread across several neighbourhoods, from game-night LoDo to the dive bars of East Colfax, with only a small club scene.

Phoenix has the dance floors, concentrated in Old Town Scottsdale, along with the student bars of Mill Avenue in Tempe and summer pool parties at the resorts. Because its districts are far apart, a night out usually means choosing one and taking a ride-hail home.

Both cities have mountains, but Denver's are on another scale. Peaks over 4,000m, alpine tundra with elk in Rocky Mountain National Park and the I-70 ski resorts give it serious hiking in summer and skiing in winter. The dry climate also makes the paved bike trails through the city usable in every season.

Phoenix's desert peaks rise straight out of the suburbs, with Camelback scrambles, South Mountain and saguaro forest in the McDowell Sonoran Preserve. They are superb from October to April, but in summer the heat shuts them down by mid-morning.

Both cities offer a solid ring of outings within two hours, and you need a car for almost all of them in either place. Denver's are mostly mountain towns: Boulder under the Flatirons, Victorian Georgetown with its narrow-gauge railway, Estes Park and Breckenridge.

From Phoenix the trips head into desert history and red rock country: hillside Jerome, the cliff dwelling at Montezuma Castle, Sedona, and Tucson with Mission San Xavier del Bac. That is the ancient Southwest that lies too far from Denver for a day.

Denver is the easier family destination. City Park pairs the zoo with the Museum of Nature & Science and its dinosaurs and planetarium. The Children's Museum, aquarium and amusement park are grouped by the South Platte, and scenic railways in the mountains are a short drive away.

Phoenix has a comparable list, with a zoo, a science centre, water parks and pool resorts. However, the attractions are spread across a huge metro area, and from June to September the heat limits outdoor time for small children. In Denver, the things to watch are altitude and strong sun.

Denver is much easier without a car. Its compact, flat downtown can be covered on foot or by the free shuttle along the 16th Street Mall, the airport train ends at Union Station, and light rail and buses reach the nearer neighbourhoods. You still need a car for the mountains.

Phoenix is a flat grid stretching for dozens of kilometres, with one useful light rail line between the airport, downtown and Tempe. Walking is limited to a few small cores, and in summer even that is punishing, so hiring a car is close to essential.

Phoenix has a little more to offer shoppers, mostly thanks to Scottsdale's luxury mall and galleries and, above all, Navajo and Zuni silver and turquoise, Hopi katsina carvings and rugs, best bought from museum shops and reputable dealers.

Denver has the edge only in outdoor gear, with big flagship stores, and in cowboy boots and hats. Otherwise it offers Cherry Creek's mall and boutiques and the vintage shops of South Broadway, with little luxury retail.

Phoenix is somewhat kinder to the wallet, mainly because its hotel prices follow the weather. Winter and spring are expensive in Scottsdale, but rooms drop sharply in summer, and chain hotels along the freeways are reasonable all year.

Denver's downtown hotels are expensive during conventions and ski season, with no comparable low season to take advantage of. Both cities usually need a rental car, and in both the cheapest days are spent outdoors, eating at taquerias.

Denver is clearly ahead here, and Red Rocks Amphitheatre is the reason: a concert between two sandstone monoliths is something people travel for. The Denver Center adds several blocks of theatre, symphony, opera and ballet, and Five Points has small jazz rooms with deep roots.

Phoenix has the usual institutions, including ASU Gammage, a round hall designed by Frank Lloyd Wright, and the intimate concert hall at the Musical Instrument Museum, but none of them is a draw in its own right. Its seasons also mostly stop for the summer.

Phoenix is clearly ahead for a restful stay, because in Phoenix the rest is right in town, while in Denver it means leaving town. In Denver itself relaxing comes down to hotel and day spas, yoga studios and sunny parks. For hot water you drive west to the historic mineral pools and steam caves of Idaho Springs, under an hour away, or stay overnight at the larger hot-spring resorts deeper in the mountains.

In Phoenix the resort is the whole point of the stay. The big properties below Camelback Mountain and across north Scottsdale are built so that you can check in and not leave the grounds for days, with golf on hand. What Phoenix lacks is anything natural or historic to bathe in, and outside the resorts the city offers little calm.