Ayutthaya or Vientiane?

Both cities are far inland, so neither has a beach. Ayutthaya's three rivers are working waterways and the Mekong at Vientiane is brown and fast, so swimming in either city means a hotel pool.

The difference is in what is close by. From Vientiane you can cool off in the river and lagoons around Vang Vieng, and from Ayutthaya the Gulf of Thailand is a drive of more than two hours. Anyone who wants beach days should add them somewhere else on the trip.

Vientiane gives you more to explore at the table. Lao cooking is the draw: sticky rice from woven baskets, larb and pounded papaya salad. The French years left baguettes stuffed with pâté and strong Bolaven coffee, and evenings bring the grill stalls and Beerlao tables along the Mekong.

Ayutthaya's food is good provincial Thai cooking with a few specialities: boat noodles eaten several bowls at a time, giant river prawns grilled by the water, and roti sai mai from the stalls near the old Muslim quarter. Past those, the night markets cover most of what is on offer.

This is where the two differ most. Ayutthaya was the capital of Siam for four centuries, and its ruins cover the whole island: the three chedis of Wat Phra Si Sanphet, the Buddha head held in tree roots at Wat Mahathat, and Wat Chaiwatthanaram at sunset. The national museum holds the gold found in the crypts.

Vientiane has less to see but more variety: the gilded stupa of Pha That Luang, the cloister of thousands of small Buddhas at Wat Si Saket, the story of unexploded bombs at COPE and the odd concrete sculptures of Buddha Park. It is a day or two of sights, while Ayutthaya can fill several days with ruins alone.

Neither city is a place for a big night out, but Vientiane has a bit more going on. Beerlao at riverside tables leads on to a few expat bars and a small number of clubs where young Lao dance to local and Thai pop.

Ayutthaya has a short strip of backpacker bars and riverside terraces looking out at the floodlit temples, and the guesthouse crowd goes to bed early. For anything livelier you have to go to Bangkok.

Vientiane is much the better base for the outdoors, though the scenery starts some way out of the city. Vang Vieng's limestone peaks offer caves, rock climbing, tubing and balloon flights. Closer in, Phou Khao Khouay has forest trails and the Nam Ngum reservoir is scattered with wooded islands.

Ayutthaya's countryside is flat rice plain and canals. The pleasures are cycling under shade trees, a long-tail boat around the island and egrets over the paddies. The nearest wild landscape is Khao Yai, about two hours away by road.

Ayutthaya has the stronger day trips because it is so close to Bangkok, an hour and a half south, with its Grand Palace and markets. Bang Pa-In's mix of Thai, Chinese and European palace buildings is only twenty minutes away, and Lopburi's Khmer temples and macaques make a third good outing.

Vientiane relies on the railway north. Vang Vieng is easy to see in a day, and Luang Prabang can be done with an early train but really deserves a night. Nong Khai's sculpture garden is just across the Friendship Bridge, though the border crossing eats into the day.

Neither city is built for children, and the two are much alike here. Ayutthaya has one strong half-day: the tree-root Buddha and the big temple grounds where children can run about. Climbing is barred on many of the monuments, though, and there is little shade at midday.

Vientiane offers a small water park, the giant statues of Buddha Park and a gentle welcome for children, but patchy pavements and the heat make days tiring. In both cities a hotel pool does a lot of the work.

Getting around is about equally easy in both, but in different ways. Ayutthaya's island is made for a bicycle. It is flat and has quiet back lanes, tuk-tuks can be hired for a half-day circuit of the ruins, and small ferries cross to the temples on the far banks.

In Vientiane the temples, riverfront and markets are all within a few blocks, so walking works better, despite the motorbikes parked on the pavements. Outlying sights such as Pha That Luang need a tuk-tuk or a ride-hailing car, and traffic is light enough for cycling.

Vientiane has something worth buying in its handwoven Lao silk and cotton. The patterns change from one ethnic group to the next and are sold as lengths or as sinh skirts in small weaving galleries, at Talat Sao and at the riverside night market.

Ayutthaya's stalls sell mostly amulets, clothes and souvenirs, and its floating markets are staged for visitors. For proper crafts, go downstream to the Bang Sai centre.

Both are among the cheapest places you could choose, and your money goes a long way in either. In Ayutthaya the extra costs are entry fees at each ruin and a tuk-tuk for the circuit, and bicycle hire costs almost nothing.

In Vientiane, imported wine, Western restaurants and polished hotels push costs up, and tuk-tuk fares need agreeing before you set off. Noodle soup, massages and Beerlao stay very cheap.

There is little live performance in either city, though Vientiane has a bit more. It has evening shows of Lao dance with the khaen mouth organ, a few bars with cover bands, and music at temple festivals.

Ayutthaya's main event is its annual World Heritage fair, when light-and-sound shows and traditional dance take place among the ruins. For the rest of the year there is little more than the odd folk performance.

Vientiane is clearly better for rest. Its Lao herbal saunas, wooden steam rooms run beside temples such as Wat Sok Pa Luang, finish with herbal tea and a massage. The whole city moves slowly, from strong coffee in the morning to an evening walk along the Mekong.

Ayutthaya offers good, cheap Thai massage, welcome after a day on the bicycle, but no bathing tradition. Its calm comes late in the day, once the tour buses leave and the riverside terraces go quiet.