Kolkata or Mumbai?

Neither city is a place to swim, but Mumbai at least has the sea. Juhu and Girgaum Chowpatty are broad sands for sunset walks, snacks and kite flying, and the ferry to Alibaug reaches cleaner water in a long day out.

Kolkata sits on the Hooghly, where nobody swims, and its nearest beaches at Digha and Mandarmani are far enough away to need a night. In both cities, the realistic place to swim is the hotel pool.

Both are first-rate food cities, and the difference is in character. Kolkata's strength is a single, deep regional cuisine: river fish in mustard, poppy seed and panch phoron, sweets from family confectioners, and layers of history in the potato-and-egg biryani, the Indo-Chinese kitchens of Tangra and the Anglo-Indian grills of Park Street.

Mumbai is broader and faster. Station carts sell vada pav, Irani cafés serve bun maska, and Malvani kitchens cook crab and pomfret in coconut, alongside dishes from across India. It also has a modern restaurant and cocktail tier in Bandra and Lower Parel that Kolkata largely lacks.

Both are former British port cities with a rich colonial legacy, so the choice is about texture. Kolkata, the old capital, offers monuments and collections: the Victoria Memorial, the Indian Museum and the strange Marble Palace. It also has a living Bengali heritage of Kalighat, Belur Math, Tagore's house and the idol-makers of Kumartuli, though much of it is crumbling and easier to read with a guide.

Mumbai's highlight is its streetscape. The Gothic station, the Victorian buildings of the Oval Maidan and the Art Deco blocks of Marine Drive face each other across open grass, and fine museums sit nearby in Kala Ghoda. Beyond that core, the sights are scattered and slow to reach.

Mumbai offers a proper night out. There are cocktail bars, gastropubs and clubs in Bandra, Khar and the old mill compounds of Lower Parel, and an older bar strip in Colaba, with dressy, busy weekends.

In Kolkata, an evening usually means drinks and dinner around Park Street or in a hotel lounge, and dry days can shut the bars entirely. Both cities close early, around midnight. Kolkata's great exception is Durga Puja, when the whole city tours the pandals until the small hours.

Mumbai has far more to offer outdoors. A forested national park with leopards and ancient rock-cut caves sits inside its northern suburbs, flamingos feed on the creek mudflats in winter, and the Western Ghats, with Matheran and the hill forts, are about two hours away.

Kolkata lies on the flat Ganges delta, so green space means the Maidan, Rabindra Sarovar and the great banyan at the Shibpur Botanic Garden. Its one big wild draw, the Sundarbans mangroves, needs two or three days on a boat.

Mumbai has the stronger single outing: the hour-long boat ride to Elephanta's carved Shiva caves. The Buddhist halls at Karla and Bhaja and the Alibaug coast add a couple more.

Kolkata's classic day follows the Hooghly upstream through the former Danish, French, Dutch and Portuguese settlements of Serampore, Chandannagar, Chinsurah and Bandel, which are easy to link by local train. Its more remarkable places, Shantiniketan, Bishnupur and Murshidabad, need an overnight stay, just as Ajanta and Ellora do from Mumbai.

Both cities welcome children warmly and both are tiring to travel with, so there is little between them. Kolkata keeps more of its attractions inside the city, with Science City, Nicco Park's rides, the old Alipore Zoo and the planetarium, plus the Maidan for running about. Mumbai's best are the Nehru Science Centre, the harbour ferries and ice cream at Chowpatty, while its theme parks are a long drive out and families do best with a car and driver.

Getting around is equally slow in both, but the shape of each city differs. Kolkata is more compact, and its north-south metro runs straight through the centre to Park Street and Kalighat. Hooghly ferries make a pleasant shortcut, and the heritage core is walkable in winter.

Mumbai stretches along a long, thin peninsula. The suburban railway is the quickest way north but crushingly full at rush hour, the metro covers only part of the city, and road traffic can turn short trips into an hour. Only the Fort and Colaba area is comfortable on foot.

Mumbai has more range. Zaveri Bazaar sells gold, Chor Bazaar sells antiques and old film posters, and Colaba Causeway and Linking Road have street stalls, while designer boutiques in Kala Ghoda and Bandra and a few luxury malls cover the top end.

Kolkata is narrower but excellent in its speciality, Bengal textiles. Gariahat and the Dakshinapan emporia sell Baluchari silk, tant cotton and kantha embroidery. New Market's Victorian hall and the book stalls of College Street are worth a wander, but there is little luxury or design shopping.

Kolkata is the cheaper trip, and the gap is mostly in where you sleep. Comfortable mid-range hotels cost very little, and food, transport and museum entry are all cheap, so only luxury hotels and imported drinks feel expensive.

Mumbai's street food, trains and rickshaws are just as easy on the wallet, but good rooms in the south of the city cost far more, and heavily taxed cocktails push a night out towards Western prices.

Language decides this one. Kolkata's arts are deep but mostly in Bengali. Group theatre fills the Academy of Fine Arts and Rabindra Sadan most evenings, so a visitor gets most from its Hindustani classical music, above all the Dover Lane Music Conference each winter, and from Tagore's songs and dance dramas.

Mumbai is easier to follow without the local language. The National Centre for the Performing Arts at Nariman Point is home to the Symphony Orchestra of India and adds jazz and dance, so Western orchestral music, rare in Kolkata, has a real home here. Prithvi Theatre in Juhu stages English plays alongside Hindi ones.

Organised rest is what tips this towards Mumbai. In Kolkata, spas are mostly limited to the big hotels and a few Ayurvedic massage centres. Its calm comes unplanned, on the ghats at first light or on the lawns of Belur Math.

Mumbai has large spas in its luxury hotels, yoga studios in Bandra and the western suburbs, and early walks along Marine Drive or the Bandstand promenade. When the city wears thin, the hills of Lonavala are close enough for a proper retreat.