Istanbul or Marrakech?

Neither city is a beach destination, but Istanbul can at least give you a swim. The Black Sea sands at Kilyos and Sile are about an hour away and warm enough in high summer, though the currents mean you should stick to lifeguarded stretches, and the Princes' Islands add pebbly coves within a ferry ride.

Marrakech sits on an inland plain, and the Atlantic at Essaouira is a long drive to cool, windy water. In practice swimming means a riad plunge pool or a hotel pool, with the Lalla Takerkoust reservoir as an occasional change of scene.

Istanbul has the deeper table. It draws on cooking from across Turkey, from Black Sea anchovies to south-eastern kebabs and Ottoman palace dishes, and you can eat well at every level, from lokanta lunch trays and fish sandwiches by the Galata Bridge to long meyhane evenings and grazing through Kadikoy's market streets.

Marrakech has distinctive dishes, tanjia slow-cooked in hammam embers, pastilla and the dusk grill stalls of Jemaa el-Fna, but the range narrows after a few days. Menus tend to repeat, alcohol is limited to licensed places, and the best meals are often home cooking in a riad.

Both cities are full of history, but Istanbul works on a bigger scale. Hagia Sophia, Topkapi, the Blue Mosque and the Basilica Cistern stand within a short walk of each other, and beyond them come Sinan's Süleymaniye, the Chora mosaics, the Theodosian walls and the palaces along the Bosphorus. A week does not exhaust it.

In Marrakech the medina itself is the monument, a medieval maze under the Koutoubia minaret, with the Ben Youssef Madrasa, the Bahia and El Badi palaces and the Jardin Majorelle within reach. It is atmospheric rather than encyclopaedic, with small museums, and two or three days cover the main sights.

Istanbul is the city for going out. Beyoglu's rooftop bars and late meyhanes, Karakoy's cocktail bars, the cheaper bar streets of Kadikoy and Moda and the summer clubs at Ortakoy all run late, often until dawn.

Marrakech is a city of evenings rather than nights. Alcohol is served only in licensed hotels, restaurants and rooftops, so the usual pattern is dinner and the spectacle of Jemaa el-Fna, with the lounge bars and a few clubs of Hivernage and Gueliz for those who want more, often at resort prices.

Here Marrakech pulls ahead. The High Atlas fills the horizon, and within about an hour and a half you can walk among the Berber villages above Imlil, follow the Ourika valley to the waterfalls at Setti Fatma or set off for Toubkal. Agafay's stony desert, dawn balloon flights and winter skiing at Oukaimeden add more variety.

Istanbul's natural side is gentler and more urban: the wooded shores of the Bosphorus, tulips in Emirgan Park in April, trails in Belgrad Forest and cycling on the car-free Princes' Islands. There is no wild country close by, and the sheer size of the city makes getting out slow.

Istanbul gives you more good days out. Ferries reach the Princes' Islands and the fishing village of Anadolu Kavagi with little effort, and Bursa, the first Ottoman capital, is a full but manageable outing. Edirne and Iznik are possible as long days.

From Marrakech most excursions head into mountains and desert rather than to other towns. Essaouira is the favourite but works better with a night there, Ait Benhaddou needs an overnight stay, and the closer options come down to foothill souks such as Asni and the mosque at Tinmel.

Families have the easier time in Istanbul. Ferry rides, the ships and submarine at the Rahmi M. Koç Museum, Miniaturk, aquariums and the seaside parks on the Asian shore give children real outlets, even if hills, crowds and cobbles are tough on pushchairs.

Marrakech has little built for children beyond a water park, camel rides and the snake charmers of Jemaa el-Fna. The narrow, motorbike-filled lanes and summer heat are hard on small children, so it works best for older, adventurous ones in spring or autumn, with a riad pool as the calm base.

Istanbul's network does far more for a visitor. A single card covers the metro, the T1 tram through the old city, the Marmaray tunnel and the ferries, and the core districts can be walked, though rush hours and road traffic can be grim.

Marrakech has no metro or tram. You walk the medina's unnamed alleys, sharing them with motorbikes and carts, take petit taxis between the old city and Gueliz, often agreeing the fare first, and need a driver or tour for anything in the mountains or desert.

What sets Istanbul apart is everything beyond the bazaar. The Grand Bazaar and Spice Bazaar cover carpets, ceramics, lamps and Turkish delight, and on top of them come Nisantasi's designer boutiques, Cukurcuma's antique shops, Kadikoy's flea markets and huge malls, so you can shop for fashion as easily as for crafts.

Marrakech's souks are just as much a reason to go, laid out by trade with lanes of leatherworkers, dyers and babouche makers. Gueliz and Sidi Ghanem add design shops reworking Moroccan crafts. Luxury fashion is almost absent, though, and the sellers' persistence wears on some visitors.

Marrakech goes further on a tight budget. Street food on Jemaa el-Fna, petit taxis, mint tea and palace entry are all cheap, and simple medina riads give real character for modest money, as long as you are patient with souk bargaining.

Istanbul can be cheap if you ride ferries and eat in lokantas, but hotels and menus in Sultanahmet, Galata and along the Bosphorus are much dearer. Entry fees at the major monuments are steep for foreign visitors, so a sightseeing-heavy stay costs noticeably more. In both cities alcohol is expensive.

Istanbul has a real stage calendar: opera and ballet at the Ataturk Cultural Centre, orchestras in modern halls, summer music and jazz festivals in historic settings, and Sema ceremonies in old dervish lodges. Beyoglu and Kadikoy add small venues for rock, Anatolian folk and jazz.

Marrakech's performance is mostly free and outdoors, with gnawa musicians, drummers and storytellers in Jemaa el-Fna every evening. It is memorable, but there is no opera or orchestra season, and beyond the square most staged shows are tourist dinner entertainment.

Both cities do bathing well, and in both you find calm by retreating from loud streets. In Istanbul that means the domed sixteenth-century hammams by Sinan, such as Cemberlitas and Kilic Ali Pasa, with tea on a terrace at Kandilli or a slow ferry ride to unwind.

In Marrakech the hammam is a neighbourhood habit, black soap and kessa scrubs in public baths or argan and rhassoul treatments in riad spas. The real difference is the riad itself, a courtyard house with orange trees and a fountain that shuts out the medina, together with the gardens of Majorelle and Agdal.