Batumi or Istanbul?

Batumi is the beach town of the two. A long pebble shore runs the full length of the boulevard, so you can swim between breakfast and lunch, and the sea there is a little warmer in high summer. The stones are coarse and the water off the centre can be cloudy after rain. For clear water and green hills sloping down to the shore, go to Gonio, Kvariati or Sarpi, all close by.

Istanbul offers the opposite kind of beach. Its sandy Black Sea strands at Kilyos and Sile are softer underfoot but an hour away and known for strong currents. Closer in, the Princes' Islands have small coves for a half day. Swimming there fits around the sightseeing.

Batumi eats well within a narrow range. Adjarian khachapuri, khinkali, walnut sauces and fish picked at the port market and fried next door make for very good meals, best in family-run places in the old town. After a few days, though, you have tried most of what the town cooks.

In Istanbul, food is reason enough to make the trip. Lunch trays in lokantas, Black Sea anchovies, south-eastern kebabs, Ottoman palace dishes and long meyhane evenings in Beyoglu and Kumkapi give you something new at every meal. Grazing through the Kadikoy market streets is a highlight in itself.

Batumi's culture is mostly modern and on show by the sea: the Alphabet Tower, the turning Ali and Nino figures and the illuminated skyline, with oil-boom houses and the Orta Jame mosque in the old town. The Roman and Byzantine fortress at Gonio is the one serious historic site, and a day covers the lot.

Istanbul is one of the world's great historic cities. Hagia Sophia, the Blue Mosque, Topkapi and the Basilica Cistern sit within a short walk of each other on the historic peninsula. Beyond them are Sinan's Süleymaniye, the Chora mosaics, the Theodosian land walls and the Ottoman palaces along the Bosphorus. A week still leaves things unseen.

Batumi's nightlife is a summer resort scene: beach clubs playing until dawn, crowded boulevard bars and casinos under towers lit up in colour. Outside July and August most of it closes, and only a few wine bars in the old town stay open.

Istanbul goes out all year and in many different styles. You can find rooftop bars over the Golden Horn, meyhanes off Istiklal that end in singing, polished cocktail bars in Karakoy and Cihangir, and cheap, crowded bar streets in Kadikoy and Moda. In summer the Bosphorus clubs at Ortakoy add the glamour Batumi aims for, on a much larger scale.

Batumi has wilder country on its doorstep. The Botanical Garden climbs the Green Cape above the sea, and Mtirala's rainforest trails and river pools are about an hour away. The Adjaristskali valley adds rafting, arched stone bridges and paragliding from the coastal hills. The same heavy rain that keeps it all green also means some days are lost to the weather.

Istanbul's nature is gentler and closer to the city. You get the wooded Bosphorus seen from a ferry, tulips in Emirgan in April, the trails of Belgrad Forest and cycling on the car-free Princes' Islands. There are no mountains within reach, and getting out of the city takes time.

Istanbul has the stronger choice of outings, and many begin on a boat. The Princes' Islands, a cruise up the Bosphorus to the castle at Anadolu Kavagi and Bursa, the first Ottoman capital, each fill a satisfying day. Edirne and Iznik are possible for those willing to make a long day of it.

Batumi's excursions are shorter and smaller. Gonio and the ruins of Petra cover the history, Kobuleti and Ureki offer a different beach, and the wine villages around Keda make a pleasant drive inland. Sarpi lets you cross briefly into Turkey, but Kutaisi's monasteries need an overnight stay.

The two are evenly matched for families, in different ways. Batumi is a summer seaside trip: a flat, car-free boulevard with playgrounds and bike hire, plus the dolphinarium, the cable car and the Ferris wheel. The pebbles hurt small feet, though, and traffic off the promenade is careless.

Istanbul works more as a city adventure in any season. Children love the ferry rides, the submarine at the Rahmi M. Koç Museum and Miniaturk. The price is steep cobbled hills, crowds at the big sights and pushchair-hostile pavements.

Batumi is a town you cover on foot. The old town, the port and the seafront boulevard lie close together on flat ground, a cycle path runs the length of the promenade, and buses or cheap app taxis reach the botanical garden, Gonio and the airport. There is no metro or tram, and once you leave the boulevard the pavements narrow and pedestrian crossings count for little.

Istanbul is no harder to manage, but there you rely on the transit network rather than your feet. One card covers the metro, the T1 tram through the old city, the Marmaray tunnel under the Bosphorus and the ferries between continents, which beat sitting in road traffic. Walking the historic peninsula and Beyoglu means steep hills, and the tram past the main sights is packed at rush hour.

Batumi is no place for a shopping trip. Beyond a few chain malls, the central market's cheese, honey and churchkhela and shops full of Georgian wine and chacha supply the best souvenirs. Enamel jewellery and felt are the craft finds.

Istanbul is one of the great shopping cities. The Grand Bazaar's hans sell carpets, kilims, lamps and leather, and the Spice Bazaar stands by the Golden Horn. Nisantasi has designer labels, Cukurcuma antiques and Kadikoy flea markets, which together cover almost every taste and budget.

Batumi stretches a budget further. Georgian meals with wine, taxis and the botanical garden are all cheap, and apartments in the towers keep rooms low for most of the year. Only July and August push seafront prices up, so June and September give the best mix of warm sea and low cost.

Istanbul can be cheap if you eat in lokantas and ride the ferries. But rooms and menus in Sultanahmet, Galata and along the Bosphorus are much dearer, and heavily taxed drinks and entry fees at the big monuments add up. Staying in Kadikoy narrows the gap.

Istanbul gives you far more to plan an evening around. The state opera and ballet perform at the Ataturk Cultural Centre, summer festivals put jazz and classical concerts in historic courtyards, and Beyoglu and Kadikoy have small venues for Anatolian folk and rock. Sema ceremonies in old dervish lodges and fasil musicians in the meyhanes are easy to find.

In Batumi you rely more on luck. The drama theatre and the music centre mainly serve local audiences, and seafront concerts happen in summer. If a Georgian polyphonic choir is performing, though, it is well worth going.

Istanbul has a living bathing tradition. In Sinan's sixteenth-century hammams, such as Cemberlitas and Kilic Ali Pasa, you lie on a heated marble stone under star-pierced domes while an attendant scrubs you down. A slow ferry or tea in Kandilli brings calm to a hectic city.

Batumi has nothing like this, since Georgia's sulphur baths are in Tbilisi. Here wellness means hotel spa floors and massage of uneven quality. Its real calm comes out of season, walking the empty promenade or the garden terraces above the sea.