Ayutthaya or Krabi?

There is no contest here. Ayutthaya stands on a river plain with no beach at all, and its rivers are for boats, not swimming, so a hotel pool is the only option. Krabi is built around the sea: the cliff-framed sand of Railay West and Phra Nang, quieter resort beaches at Klong Muang and Tubkaek, and islands a short longtail ride away.

If your trip covers both, make Ayutthaya the history stop and save the swimming days for Krabi, ideally between November and April, when the Andaman is calm.

Both places eat well and cheaply without being food destinations, but the cooking is different. Ayutthaya serves central-plains river food: boat noodles eaten several small bowls at a time, giant river prawns grilled by the water and roti sai mai wrapped around threads of spun sugar.

Krabi cooks the spicier southern way, with yellow fish soups, khao mok gai and roti breakfasts shaped by its Muslim communities, and its sea fish and prawns are the highlight. Ao Nang also serves pizzas and burgers, which Ayutthaya hardly does, but the evening market in Krabi Town is where the local food is.

Here Ayutthaya is in another league. Four centuries as the capital of Siam left a UNESCO-listed island of prangs, chedis and crypts. Highlights include the Buddha head held in tree roots at Wat Mahathat, sunset at Wat Chaiwatthanaram and the old Portuguese and Japanese quarters to the south.

Krabi's sightseeing comes down to the long climb to the Tiger Cave Temple, a few Chinese shophouses in Krabi Town and the caves of Khao Khanab Nam. People go there for the scenery, not for monuments.

Neither is a party town, but Krabi gives you more of an evening. Ao Nang's beach road and its small alley of late bars, plus the hammocks and fire-spinning on Railay, keep people out after dark, and Phi Phi is a ferry ride away if you want a full night. Ayutthaya has a short strip of backpacker bars and riverside drinks facing the lit-up temples, and most people are in bed well before midnight.

Krabi's limestone landscape is one of the main reasons people travel to southern Thailand. Sheer karst towers rise out of the sea and the jungle, and Railay and Tonsai are famous for sport climbing. The mangroves of Ao Thalane and the Hong islands make for excellent kayaking, and there are also snorkelling, diving and rainforest pools.

Ayutthaya's outdoors is flat rice field and river: a bike ride under big trees, a long-tail boat around the island at dusk, egrets over the paddies. For real wild country from there you need Khao Yai, about two hours away by road.

Ayutthaya has the better choice of places to visit. Bangkok and the Grand Palace are an easy train ride south, the Bang Pa-In summer palace is twenty minutes away, and Lopburi's Khmer temples and macaques are a train ride north.

Most outings from Krabi are boat trips for the scenery. For actual places to see, there are Phi Phi's village, Koh Lanta's stilted Old Town and the fishing villages of Koh Yao Noi, but no major heritage site within easy reach.

Krabi is the easier place with children, mainly because of the water. In the dry season the coves at Klong Muang and Phra Nang are shallow and warm, and the resorts have pools and kids' clubs. It has no zoos or theme parks, though, and the open longtail boats and rough monsoon seas need planning with very young children.

Ayutthaya holds children's attention for a morning, with the Buddha head in the tree roots and open temple grounds to run around in. Climbing on many of the ruins is not allowed, however, and the midday heat on the shadeless sites is hard on small ones.

Ayutthaya is the simpler place to get around. The old city fits on a flat island a few kilometres across, so a bicycle, a tuk-tuk hired for half a day and the small river ferries cover nearly everything.

Krabi is spread out between Krabi Town, Ao Nang and the northern beaches, which are linked by songthaew pickups, taxis and hired scooters. Railay can only be reached by longtail boat, and the boats stop when the sea is rough. In both places the heat limits how far anyone wants to walk.

Ayutthaya's shopping follows the temples and Krabi's follows the beach, and in both you will mostly browse rather than buy. In Ayutthaya that means clothes and Buddha amulets at the night markets, souvenir stands at the gates of the big ruins and trinkets at the staged floating markets. The one real speciality is the woven goods of the royal crafts centre at Bang Sai, downstream towards Bangkok.

Krabi sells what a beach stay needs. Ao Nang's main road has swimwear, souvenirs, knock-off goods, tailors and a few small craft shops, and Krabi Town's weekend walking-street market is more local. You will not find boutiques or design labels in either place.

Both are cheap, but your money goes further in Ayutthaya. Its riverside guesthouses and hotels with pools cost little even by Thai standards, bicycle hire is almost free, and the separate entrance fee at each ruin is the main expense.

In Krabi, costs depend on where you stay: Krabi Town is very cheap, Ao Nang costs more, and Railay is the most expensive because everything arrives by boat. On a beach stay, island tours, longtail fares and national park fees for foreigners add up in a way that Ayutthaya's costs do not.

Neither has a theatre or concert hall worth planning around, but the little on offer is different in each. Ayutthaya's big occasion is its annual World Heritage fair, with light-and-sound shows and traditional dance among the ruins, while Krabi has fire-spinning on the beaches, cover bands in bars and Muay Thai fights staged for visitors.

Krabi is the better place to rest. Massage shops line every street, and the resorts at Klong Muang, Tubkaek and Railay have full spas with sea views. Yoga is easy to find, and the forest pools of the Hot Springs Waterfall at Khlong Thom are about an hour's drive away.

Ayutthaya offers simple, cheap Thai massage after a day on a bicycle, and slow evenings on a riverside terrace once the tour buses have gone. It has few proper spas and no bathing tradition.