Istanbul or Dubai?

Of the two, Dubai is the beach city. Its shore is a continuous run of pale sand on calm, shallow water, stretching from Jumeirah and Kite Beach to JBR and Umm Suqeim. The resort hotels on Palm Jumeirah make the beach the centre of the stay. In midsummer the water is bath-warm and the sand too hot by mid-morning, so swimming moves to the early and late hours.

Istanbul lives beside the water rather than in it. The proper beaches, at Kilyos and Sile, are about an hour north on the Black Sea. They are sandy but known for undertow, and only warm enough in high summer. The pebbly coves of the Princes' Islands make a pleasant half day, not a beach vacation.

Both cities eat well, but Istanbul's cooking belongs to the place. Turkish food arrives from every region, alongside Ottoman palace dishes, lokanta trays at lunch and nights of meze and rakı in the meyhanes of Beyoglu and Kumkapi. Kadikoy's market streets are made for grazing.

Dubai's strength is the food of the people who live there: Keralan curry, Pakistani karahi and Iranian kebabs in Deira and Karama, with chef-led dining rooms and Friday brunch in the towers. Emirati cooking is hard to find, and wine with dinner means a licensed hotel venue.

This is where the two cities are furthest apart. On Istanbul's historic peninsula, Hagia Sophia, Topkapi Palace, the Blue Mosque and the Basilica Cistern are a short walk from each other. Beyond them lie Süleymaniye, the Chora church, the Theodosian walls and the Bosphorus palaces, and the city's long run as an imperial capital rewards a week or more.

Dubai offers modern spectacle instead, with the Burj Khalifa and the Museum of the Future. Its older layer along the Creek is small: the wind-tower houses of Al Fahidi, Al Shindagha and the Deira souks. Two or three days covers it.

Istanbul's nights are looser and more varied. Beyoglu mixes rooftop bars with small bars and meyhanes that end in singing, while Kadikoy and Moda are younger and cheaper. In summer the clubs on the Bosphorus shore at Ortakoy keep going until dawn.

In Dubai, going out happens inside hotels and licensed venues: big-name DJ clubs, rooftops above Sheikh Zayed Road, beach clubs on the Palm and the long weekend brunch. It is polished and runs late, but there are no bar streets and no casual end to the night.

Neither is a wilderness city, but Istanbul has more green within reach. You can walk the wooded Bosphorus shore at Bebek and Rumeli Hisari, see the April tulips in Emirgan, follow the trails in Belgrad Forest or cycle on the car-free Princes' Islands.

Dubai's outdoors is desert. There are dune drives and camel rides at Al Marmoom an hour inland, kitesurfing at Kite Beach and the Hajar mountains at Hatta, about ninety minutes away. From May to September the heat rules out most of it except at dawn.

Istanbul has the edge, largely because so many of its outings go by water. Ferries reach the Princes' Islands and Anadolu Kavagi on the upper Bosphorus, and Bursa's Green Mosque and silk market fill a day. Edirne and Iznik make long days, and Gallipoli needs a night.

From Dubai, three outings stand out: the Grand Mosque and the Louvre in Abu Dhabi, Sharjah's heritage quarter and museums next door, and the oases and forts of Al Ain. Beyond those it is mostly desert and road.

Dubai is built around families who want attractions laid on. Theme and water parks, resort kids' clubs and air-conditioned everything make long days easy for parents. The drawbacks are that most outings need a taxi and the summer heat keeps everyone indoors.

Istanbul gives children the warmer welcome on the street, with waiters fussing over babies and families out late on summer evenings. The Rahmi M. Koç Museum's submarine and Miniaturk are good outings. Steep cobbles, crowds at the main sights and pavements that defeat pushchairs are the cost.

Istanbul is the easier city to move through as a visitor. One card covers the metro, the T1 tram through the old city, the Marmaray tunnel under the Bosphorus and the ferries. The historic core, Galata and Beyoglu can be walked if you can manage the hills. Rush-hour crowds and slow taxis are the price.

Dubai's driverless metro is clean and simple along Sheikh Zayed Road and around the Creek, but the city stretches some 50km and was laid out for cars. Palm Jumeirah, the beaches and the theme parks mean taxis, and the heat makes walking between stations tiring.

Both are serious shopping cities, and the difference is the setting. Dubai shops indoors and at scale, in the Dubai Mall and the Mall of the Emirates, with great depth in luxury brands, watches and jewellery. The Gold Souk and the spice and perfume souks of Deira are its older side.

In Istanbul more happens at street level and more is handmade. The Grand Bazaar and the Spice Bazaar, with haggling and streets grouped by craft, sit beside designer Nisantasi, the antique shops of Cukurcuma and the flea markets of Kadikoy. Carpets, kilims, tiles and towels are the classic finds.

Your money goes considerably further in Istanbul. Lokanta lunches, simit, fish sandwiches and cheap ferries keep everyday costs low, although hotels in Sultanahmet, fees at the big monuments and heavily taxed alcohol push the total up.

Dubai is expensive in the winter high season, when resort rates, observation decks, theme parks and alcohol are all dear. Eating in Deira and Karama and riding the metro help. In summer hotel rates fall sharply for anyone who can take the heat.

Istanbul has a resident scene of its own, which Dubai lacks. The state opera and ballet perform at the Ataturk Cultural Centre, and summer festivals put jazz in historic courtyards. Between Sema ceremonies, fasil musicians in the meyhanes and the small venues of Beyoglu and Kadikoy, you can find music without planning, though most theatre is in Turkish.

Dubai Opera brings strong touring ballet, musicals and orchestras in the cooler months, and big tours fill the arena. Dubai is a place to book a particular show, not one where you come across music by chance.

Istanbul has a living bathing tradition. Sinan's sixteenth-century hammams, such as the Cemberlitas, Haseki Hürrem and Kilic Ali Pasa, still scrub visitors on heated marble under domes pierced with star-shaped skylights. A slow ferry or a tea in Kandilli brings the rest of the calm.

Dubai's version is the resort spa: high in standard, air-conditioned and comfortable in any season, with hammam rituals borrowed from elsewhere. Resting there means staying put at the hotel, or going to a desert retreat inland for real silence.