Myanmar: cruising the Irrawaddy River provides an opportunity to visit a remarkable shrine

I'm staring into the eyes of a garishly-painted statue of an ogre queen in a dingy shrine at Mount Popa in central Myanmar, making a silent contract. If the goddess grants my wish – pathetically, I'm asking to find my soulmate – I promise to help clean up her beloved countryside, whether by donation or physical action. I think it's a fair enough deal – after all, we could both do with a little help.

According to Tu Tu, the guide accompanying us on this day excursion from a Scenic cruise along the Irrawaddy River, I'm in with a shot as long as I promise to uphold my end of the bargain. Several years ago, Tu Tu tells me, she made a deal with Mae Wunna, the most powerful spirit worshipped at this popular pilgrimage site; and after the goddess revealed herself in the form of a large green frog during a near-miss car accident, Tu Tu was granted her wish for love, meeting her future husband just two weeks later.

"Next time I went to Mount Popa, I thanked her very much as I was getting married," Tu Tu says. "I was 36 years old and wanted children right away. I promised I would come back if she gave me a baby – and then I conceived on my honeymoon. This is why I now believe in the Queen of the Mountain."

Mount Popa is an extinct volcano that rises 1518 metres above sea level, about 50 kilometres from the dusty archaeological site of Bagan. The fertile soil and temperate breezes in the area are conducive to the production of roses, strawberries, bananas, mango and papaya. The centrepiece of this verdant oasis is a dramatic, sheer-cliffed basalt plug topped with a gilded temple and monastery, looming surreal above the jungle like a magical, multi-spired fairytale castle.

Mount Popa, meaning 'flower' in Sanskrit, is said to be the home of the most powerful "nats", the spirits of heroic ancestors who met a violent death and now inhabit the mountains, forests and rivers. Before Buddhism was introduced to Myanmar in the 11th century, nats were worshipped and feared by animist believers who made animal sacrifices to appease the vengeful spirits. Today, even devout Buddhists such as Tu Tu flock to the shrine, handing promises and money to the 37 nats represented in the pantheon via a chanting medium.

The green-cloaked goddess I've approached should be sympathetic to my romantic plight. She had her own special love story, albeit a Romeo and Juliet tragedy. According to legend, Mae Wunna was a flower-eating ogress who lived a solitary life on the slopes of the volcano. One day, she met an Indian Muslim servant named Byatta, who had been sent by King Anawrahta – founder of the Bagan empire in the 11th century – to fetch flowers from the forest. After falling in love, they married and had two children.

When the king heard of their forbidden union, however, he had Byatta executed, and Mae Wunna died of a broken heart. Fortunately, the lovers were resurrected as nats, and now dwell on top of the mountain. Their sons went on to fight in the royal army, but were also executed by the king after failing to provide bricks to build a pagoda. As luck would have it, they too became nats, whom the repentant king ended up worshipping – thus marking the start of the fluid relationship between Buddhist and animist beliefs.

My contract with the Queen of the Mountain locked in, we begin our descent up the 777 stairs to the peak, crowned by a Buddhist temple and monastery known as Taung Kalat.

It's the end of the dry season in Myanmar, counting down the sweltering days to the exuberant New Year water festival, Thingyan. The summer holidays have brought out the crowds and the covered passageway is fetid with the sweat of pilgrims squeezing past vendors selling plastic toys, souvenir T-shirts, bowls of noodles and bottled yellow blossoms, called champac, the local flowers collected by Byatta in the forest and now given as an offering to the nats.