Cadiz or Zaragoza?

This is the widest gap between the two cities. Cadiz is surrounded by the Atlantic. It has the sheltered cove of La Caleta in the old town, several kilometres of sand at Playa Victoria and the Costa de la Luz within an hour. The levante wind will spoil the odd day.

Zaragoza is more than 200km from the Mediterranean, and nobody swims in the Ebro. In summer you cool off in the city's open-air pools, so if you want beach time, plan it as a separate part of the trip.

Both cities eat tapas, but they cook very different things. Cadiz is all about the sea: paper cones from the freidurías, shrimp fritters, almadraba tuna and cold fino or manzanilla. For seafood it has the better table.

Zaragoza cooks for an inland appetite, with ternasco lamb, migas and borage with clams. You eat them on a crawl through the bars of El Tubo, each known for one dish, with generous reds from Cariñena or Somontano. Neither city offers much international cooking or fine dining.

The two cities have about the same depth of history, but very different pasts. Cadiz was a Phoenician port and later ran Spain's trade with the Americas. You see that in its houses topped with watchtowers, the gold-domed cathedral, the Roman theatre in the Pópulo and the oratory where the 1812 constitution was signed.

Zaragoza has the grander monuments: the Basílica del Pilar with its Goya ceilings, the Mudéjar wall of La Seo and the Islamic palace of the Aljafería, with Roman ruins in museums below the streets. Each city fills two or three days.

Zaragoza gives you the better night out. Students fill the bars around Plaza San Felipe and the Casco on Thursdays and at weekends, and a handful of clubs stay open into the early morning. For a week and a half each October, the Fiestas del Pilar keep the streets full until dawn.

Cadiz is quieter outside summer, when the terraces along Playa Victoria stay open late. The big exception is February's Carnival, when the whole city parties through the night.

Cadiz has more to do outdoors. Flamingos and spoonbills feed in the salt pans and marshes of the bay, Tarifa is a kitesurfing centre with boat trips to see dolphins and whales, and both the Grazalema peaks and the Doñana wetlands are within reach.

Zaragoza is surrounded by dry steppe swept by the cierzo. The paths along the Ebro and the city parks are good for walking and cycling, but for the beech woods of Moncayo, the Mallos de Riglos and the Bardenas Reales you need a car.

From Cadiz, the day trips stay in Andalusia, while Zaragoza sits on the high-speed line between Spain's two largest cities. Trains and the bay ferry from Cadiz reach sherry country in Jerez and El Puerto, and Seville is under two hours away. With a car you can reach the white towns of Vejer and Arcos.

Zaragoza's trains make Madrid or Barcelona a realistic day out. Closer to home, a hire car takes you to Loarre castle, the ruined old town of Belchite and the Mudéjar cathedral at Tarazona.

Cadiz gives children a beach, and Zaragoza gives them an aquarium and a funfair. In Cadiz the sand is the plan for the day, with lifeguards on Playa Victoria and calm water at La Caleta, but almost nothing is built specially for children.

Zaragoza has no sea. Instead it has the river aquarium on the Expo site, the playgrounds of the Parque del Agua and a small amusement park beside Parque Grande. In both cities, plan your days around the summer heat at midday.

Both centres are flat and best seen on foot. The old town of Cadiz is a grid of streets with little traffic that you can walk across from shore to shore. Buses run along the isthmus, and trains and the bay catamaran reach the nearby towns, though for the Costa de la Luz you need a hire car.

Zaragoza is more spread out, so the tram, buses and bike-share do more of the work. Delicias station links it quickly to the rest of Spain, and rural Aragon is again easier with a car.

Neither city is a shopping destination, but Zaragoza has more of it. Chains and a classic department store line Paseo de la Independencia, older shops and pastry makers fill Calle Alfonso I, and a very large shopping complex sits on the city's southern edge.

Shopping in Cadiz is smaller and more local, centred on Calle Ancha and Plaza de las Flores, and the best things to take home are fans, ceramics, flamenco fashion and sherry. For serious shopping, people in Cadiz go to Seville.

Zaragoza is the cheaper stay, mainly because central hotels are good value for most of the year. Only the October fiestas push room prices up, and the Pilar costs nothing to visit.

In Cadiz, eating and drinking are just as easy on a budget, but beds are the problem. The old town has few hotels, and they fill up in summer and at Carnival. Staying near Playa Victoria, or coming in spring or autumn, keeps the cost down.

Cadiz has the more distinctive stage. In the Santa María quarter, small flamenco peñas perform alegrías for audiences who know the forms well. The Gran Teatro Falla hosts the satirical chirigotas of Carnival and an autumn festival of Ibero-American theatre.

Zaragoza is stronger for orchestral music, with touring orchestras and jazz at the Auditorio, and its own folk tradition is the jota. If you want a performance with real local character, though, Cadiz is the better bet.

Neither city has a bathing tradition, and both rely on hotel spas and Arab-style baths, so the difference lies in what is nearby. From Cadiz, the resort spas with sea-water treatments at Novo Sancti Petri are a short drive away, and the city's slow days of walks on the sea walls and sunsets over La Caleta do the rest.

Zaragoza's nearest thermal waters are at Alhama de Aragón, more than an hour away. In the city you relax with strolls along the Ebro and afternoons in Parque Grande, though the summer heat and the cierzo can be tiring.