Kerala or Rajasthan?

This is the widest gap between the two. Kerala has a long, palm-lined coast, from the red cliffs of Varkala and the small bays of Kovalam to the village sands of Marari and the emptier north around Bekal. The sea is warm enough to swim in all through the dry season, but the surf is strong, so stay between the lifeguard flags.

Rajasthan has no coast at all, and its lakes at Udaipur and Pushkar are for looking at, not swimming in. A courtyard pool in a heritage hotel is as close as it gets.

Both are cheap and excellent for everyday eating, but Kerala has the richer table. Its cooking draws on Syrian Christian, Mappila and Hindu traditions. You can go from appam and stew in Kochi to Malabar biryani in Kozhikode and a banana-leaf sadya, with grilled pearl spot fish on the backwaters.

Rajasthan's desert cooking is heavier and mostly vegetarian, built on ghee, dal baati and ker sangri, with laal maas for meat-eaters. Its best food is on the street: kachori in Jodhpur, Bikaner bhujia and Jaipur's sweet shops. Neither is a place for drinking.

For sightseeing, Rajasthan is far ahead. Amber Fort, Mehrangarh, Udaipur's City Palace and the lived-in fort city of Jaisalmer are among India's great monuments. Beyond them are Chittorgarh, Kumbhalgarh, Ranakpur and the painted towns of Shekhawati, enough for a fortnight without repeating yourself.

Kerala's history is quieter and kept to a few places. In Fort Kochi and Mattancherry, Portuguese, Dutch and Jewish heritage all sit within a short walk, and the wooden Padmanabhapuram Palace is outstanding. But many of the great temples admit only Hindus, so visitors often see them only from outside.

Neither has nightlife worth planning a trip around, and in both the evening usually ends soon after dinner. The difference is the setting. In Kerala the liveliest spot is the candlelit clifftop at Varkala in the dry season. Elsewhere it means hotel bars or a rough toddy shop.

Rajasthan's evenings are rooftop dinners facing a lit-up fort. Jaipur has cocktail bars in heritage hotels and the odd club night, while Pushkar is officially dry.

Kerala's landscapes are greener and more varied. The backwaters around Alappuzha and Kumarakom are best seen slowly from a houseboat. Inland, the Western Ghats hold the tea hills of Munnar, wild elephants at Periyar and the trekking trails of Wayanad.

Rajasthan's scenery is drier and starker. You can spend a night in the dunes near Jaisalmer, have a real chance of seeing a wild tiger at Ranthambore and watch winter birds at Keoladeo. The range is narrower, the summer heat makes the desert punishing and the tiger parks close through the monsoon.

Rajasthan is the better place to stay put and take outings. From Jaipur, the Abhaneri stepwell, Bhangarh and Samode are all within about two hours. Udaipur, Jodhpur and Jaisalmer each have their own temple towns, forts and villages for a full day out.

Kerala is toured as a circuit rather than from one base, so there are fewer outings. The best are the Muziris heritage sites near Kochi, the temple town of Thrissur and the long drive from Thiruvananthapuram to Kanyakumari at India's southern tip.

Neither is easy with small children, but Kerala is the gentler of the two. It is calmer and cleaner, children enjoy a houseboat night and the boat trips at Periyar, and a resort pool at Marari makes a restful base. The sea is often too rough for young swimmers, though, and the hill roads bring on carsickness.

Rajasthan works best for older children who want adventure: ramparts to explore, camel rides, a desert camp and a tiger safari. With chaotic traffic, few pavements and long drives, it is harder going with the youngest.

In both, most visitors hire a car and driver, and the roads are slow. Kerala has a coastal railway linking its main towns and ferries across Kochi's harbour, but reaching Munnar or Thekkady means hours of hairpin bends.

Rajasthan's distances are longer, so a trip between cities takes most of a day by train or road. In its old cities, traffic and animals make walking tiring. Udaipur's lakeside and Jaisalmer's fort are easy on foot, as are Fort Kochi and Varkala in Kerala.

Rajasthan is one of India's great shopping regions, and Kerala is not. Jaipur's bazaars sell gems, silver, blue pottery and block-printed cottons from Sanganer and Bagru, and designer boutiques rework the same crafts. Each other city adds its own speciality, from Udaipur's miniature paintings to Jaisalmer's mirror-work. Expect to bargain, and expect drivers and guides to steer you to shops that pay them commission.

Kerala's shopping is smaller and simpler. There are spices and antiques in Jew Town, tea and cardamom from the hills and kasavu cloth woven at Balaramapuram.

Both are cheap by any international measure, with food, trains and auto-rickshaws costing very little. What pushes the bill up differs. In Kerala it is a private houseboat, a backwater resort or a long Ayurveda programme. In Rajasthan it is the palace hotels, some of the most expensive stays in India, and higher room rates in Jaipur and Udaipur in winter.

Kerala has the more striking performance culture. At Kathakali shows in Fort Kochi and Thekkady you can watch the actors being made up first, and Kutiyattam theatre is still performed in temple theatres. In north Malabar, the all-night Theyyam rituals and the drums and elephants of the Thrissur Pooram are like nothing else in India.

Rajasthan's strength is folk music: the Manganiyar and Langa singers of the desert and the Kalbelia dancers. Visitors mostly see them at hotel and desert-camp shows or at Bagore ki Haveli in Udaipur. The autumn folk festival inside Mehrangarh is the high point of the year.

Kerala is the home of Ayurveda, and many people come for that alone. Retreats around Kovalam and Varkala, on the backwaters at Kumarakom and in the Wayanad hills offer anything from one oil massage to weeks of supervised panchakarma. The slow pace of the place does the rest.

In Rajasthan, rest is something you have to arrange. A palace or lakeside hotel near Udaipur, or a spell of yoga classes in Pushkar, can give you a calm few days, but outside them the towns are loud.