Ayutthaya river cruise, home by boat.

Founded in 1350, Ayutthaya became the second great capital of Siam, following Sukhothai. Its island setting, ringed by three rivers with a link to the Gulf of Thailand, made boats the roads of its golden age. A day trip that ends on the river brings that idea back, at a gentler speed than the traders of the old kingdom ever managed.

The Chao Phraya itself is the most important waterway in Thailand, formed where the Ping, Wang, Yom and Nan rivers meet at Nakhon Sawan. A Bangkok to Ayutthaya river cruise follows this same water. The stretch you ride runs south from the old capital, past the sights that Bangkok shows its visitors from the water, and ends in the city where the day began. A few hours of sightseeing, then home on the water, is a plan the old river city seems built for, and it needs no special preparation beyond a hat and an early night.

The national tourist authority notes that the country grew up on riverbanks that fed people with rice and fish. Seen that way, the cruise is not a bonus after the temples but the second half of the same story: a country, a city and a river that shaped both. That is the context behind every picture you will take on the day, and it is why the temples and the river belong in one booking and not in two separate trips on two different days of your holiday.

The dress code is firm. Shorts, tight or torn pants, mini skirts, sportswear, sandals and sleeveless shirts are all out, and a pair of trousers or a scarf can be bought on the spot for approximately 100 Thai Baht. A sensible outfit is thin long trousers or a maxi skirt, a top with sleeves and shoes that cover the toes.

Round it off with a hat and sunscreen for the open ruins, some water, and a few small baht notes for drinks and souvenirs. The coach and the boat are shelter, but the temple stops are in the open air, and the walking is on uneven brick. Choose shoes that are easy to slip off if a hall asks for it, and carry a slim bag instead of a big pack, because you will walk and sit on stone for hours.

A child of 1 or younger rides free beside a paying adult. With a baby, pack a light sun cover and plan around nap times, since each temple stop lasts 30 to 40 minutes. Dress the little ones for heat, and take a spare top in case of spills at lunch. Light, breathable fabrics in a long cut are the answer to both the dress code and the heat.

This is not the only Ayutthaya day with a boat. A coach-and-river-boat day begins at $25 for 8 to 9 hours, with a river boat of 45 minutes. A heritage day that finishes on a sunset boat begins at $30. Each of these is a different shape of day, so compare the stops and the boat time rather than the fare alone, and read the option names, which decide what the fare includes.

Add Bang Pa-In Royal Palace and a long-tail ride of 30 minutes and the fare becomes $82. A slow river boat of 5 hours, at $86, makes the river itself the destination. The price page on this site sets them out side by side. Our price guide lines them up, so you see the whole field before booking.

The difference is the length of the boat. On our day it is 2 hours and sits at the end, which suits travellers who want a long rest after the ruins. On the cheaper days it is a short cruise in the middle, which suits travellers who want more stops at a lower fare. The right pick depends on whether you want rest or range, and on how much of one day you can spare away from the city.