Sunset in Bagan, a seat of Burmese royalty from the ninth to the 13th centuries. I’ve scrambled up to the top of the Shwesandaw Pagoda, one of 2,000 ancient monuments scattered across the plain on the bank of the Irrawaddy, and am perched on a ledge, next to a crowd of monks with iPads. The river glints in the distance as the sun begins its descent towards a row of hills, the warm sandstone around me assuming a rosy glow. Pagodas, some stepped, some rounded, pierce the horizon as far as the eye can see. Dozens of other travellers have clambered up here, too, cameras poised, waiting for the perfect shot (either that or inner peace). I hear voices from Britain, Japan and the US as well as Australia, although people fall silent as the sun finally disappears in a fiery ball.

Sanctuary Ananda, a luxury river cruiser sailing the Irrawaddy

Bagan is without doubt one of the highlights of my visit, for its sheer richness and immense scale; despite the crowds at sunset, you can pick your way round any number of crumbling temples all alone. It’s here that we embark the swish Sanctuary Ananda, one of several luxury vessels offering cruises on the Irrawaddy. Over a week, we are to sail to Mandalay and back again.

The plain at Bagan is studded with hundreds of temples

Ananda is a sharp contrast with the simplicity in which most locals live. Built in Yangon, the boat is adorned with dark wood fittings and tasteful objets d’art, the wooden sun deck scattered with colourful cushions and sunloungers around a small pool. The accommodation is some of the most luxurious on the river, each cabin featuring polished wood, stripped floors and sumptuous silks and thick cottons. The river views from the floor-to-ceiling windows are gorgeous, although fearsome clouds of insects at sunset keep us inside, rather than on our balcony.

Golden temples and stupas line the riverbanks

The crew, all Burmese, are unfailingly charming and friendly without being obsequious. The gentleness of the locals is all the more surprising, given what they’ve been through, and is what I quickly grow to love about Myanmar. Although the country is perched on the brink of a tourism boom, it remains largely unspoiled. Outside the cities, daily life hasn’t really changed. Women still paint their faces with a yellow paste made from the bark of the thanakha tree and men still wear the longyi – a kind of sarong. Life revolves around the temple and in addition, superstition governs everything. On full moon days, which are special in the Buddhist calendar, nobody seems to do much work.

Sunset at the U Bein bridge outside Mandalay

Every day, there are visits to temples, markets and local villages. But there’s no pressure to follow a relentless sightseeing programme. One day, I duck out of the tour and spend a lazy afternoon on deck, half-dozing in the sun, listening to roosters crowing and watching a green bird with red wings diving for insects.

North of Mandalay, I get up before dawn to visit the village of Sin Kyun, in which Sanctuary Retreats sponsors the library. Pink streaks are only just beginning to light the sky but the village is already bustling with activity; as luck would have it, we’ve turned up on the chief’s birthday and he has prepared breakfast for the whole community, including us. A great vat of oily, yellow-tinted fish-head soup simmers over a crackling wood fire. A small crowd gathers to watch; we stand out with our cameras and sunglasses and politely refusing the brew is clearly not an option. The soup is tangy and tasty, although I don’t quite manage the fish heads.

There are no jetties, so Ananda ties up to the riverbank

On the way back to the boat, tiny children skip behind us along the dusty path, chattering. Women sit outside their houses, returning my greeting of ‘Mingalaba’ (‘auspicious wishes’, the most important Burmese term you’ll learn) and weaving hats to sell in the local market.

Despite the unexpected success of the fish soup, Burmese food turns out to be disappointingly dense and fatty. On board, we eat mostly Thai, with Burmese influences, prepared by Chef Sumet, a big TV celebrity back in Thailand with many years under his belt at The Mandarin Oriental, Bangkok. His food is sublime. We binge on salads of morning glory and crushed peanuts; shredded green papaya with yellow limes; and chilli noodles for breakfast. I estimate that I’m downing six curries or noodle dishes a day, it’s so good.

Ananda’s crew are all from Burma

Luckily, there’s a spot of calorie-burning in store on a day trip to Mount Popa, a couple of hours’ drive from Bagan. As the lowlands swell into gentle, forested foothills, we’re confronted with the sheer-sided volcanic plug of holy Taung Kalat, a startling skyscraper of solid rock rearing improbably out of the trees with a cluster of gold stupas clinging precariously to the top, 800 steps up. The rock is said to be inhabited by nats, or spirits, who mustn’t be displeased, so nobody is allowed to climb it if they’re wearing red, black or green. Climbing up means running the gauntlet of dozens of wily macaques, adept at stealing sunglasses or spraying tourists with cans of drink like football hooligans, but the views, all the way back to Bagan, are worth it.

Looking across the Irrawaddy’s flood plain from Mount Popa

In Mandalay, we visit the U Bein Bridge, the world’s longest teak bridge, which spans a lake outside the city. We set off across the water in a flotilla of rowing boats, shutters clicking madly as the sky turns orange and the spindly bridge with its cargo of monks, tourists, cyclists and women carrying packages on their heads is back-lit by the setting sun in perfect silhouette.

On our final night in Bagan, Ananda is tied up to a sandbank with views of the pagodas as far as the eye can see across the plain. The crew set up a barbecue ashore, lit by flaming torches. A dark red moon hoists itself over the plain and soft floodlights come on, illuminating the shadowy sandstone temples from below. It’s magical.