For three years, Nguyen Trung Dung has never missed an opportunity to admire the terraced fields in Mu Cang Chai (Yen Bai Province) and Hoang Su Phi (Ha Giang Province) during the harvest season in September. To enrich his photo collection, he happily travels nearly 2,000km from HCM City to the northern region.

Terraced fields in Ha Giang

"The breathtaking scenery of immense terraced fields is reward enough for those long trips," said the engineer, 50, who proudly shares his collection of thousands of photos of northern mountainous regions with his friends on Facebook.

The magnificent terraced rice fields of ethnic minority tribes, with yellow ripened paddy grains and seemingly endless stretches of flowers, have transfixed viewers for generations.

The terraced fields appeared in Mu Cang Chai and Hoang Su Phi several centuries ago. Even before being recognised as national tourist attractions by the Ministry of Culture, Sports and Tourism some years ago, they had already become hugely popular destinations with local adventurers as well as foreign travellers.

Ha Giang is famous in September for its yellow terraced fields, but in October, the province is best known for pink tam giac mach ("triangle oat") flower fields.

"Tam giac mach" flower in Ha Giang

Local residents say that once upon a time, the inhabitants of northern mountainous areas mainly lived on corn and rice. One day, all corn and rice in the house were nearly exhausted, but the fields could not be harvested. The villagers were very hungry. Suddenly, they smelt a scent in the wind. They went along the ravine and found a field of tiny wild flowers with triangle-shaped leaves.

The villagers brought the seeds of the flowers home to use in place of corn and rice and called them tam giac mach.

Since then, the ingredient has been used to make bread or mixed with corn to make delicious local wine.

There are other places to contemplate tam giac mach flowers such as Bat Xat and Muong Khuong districts in Lao Cai province, and Tra Linh and Trung Khanh districts in Cao Bang Province.

However, the most popular destination is Ha Giang Province – specifically Sung La, Lung Cu and Xin Man districts, familiar names to many travellers.

The flower blooms in late October or early November depending on the cultivating time. Tam giac mach flowers often have three colours: light pink, glistening purple and dark red. In the bright sunshine, it looks like a watercolour painting. Its wild and endless beauty has seduced many romantic people.

"It's magical to see the slopes and valleys of Ha Giang turn red," said teacher Van Nhung, 25. "The feeling of being immersed in a sea of flowers is stunning."

Flower travelling and photographing has become a popular pursuit among young people. Besides Ha Giang, many other mountainous regions in the North attract romantic hearts with their flowers.

In spring, people often flock to Mount Fansipan in Lao Cai province to see poinsettia blossoms.

Moc Chau Plateau in Son La province draws visitors in November with endless fields of cabbage flowers, mustard green flowers and poinsettias. In spring, apricot and plum blossoms cover the plateau in white.

Mustard green flower in Moc Chau plateau

Flower travelling is growing so popular that tour companies now offer inexpensive seasonal "flower tours".

Tour operator Tran Ngoc Van said such trips are targeted at young people, especially those passionate about photography.

The mustard green flower and tam giac mach season in the Northwest region coincides with the wedding season in October and November, so this tour attracts many couples, she said.

The dream-like yellow mustard flower fields provides great scenery for the wedding photos of any young couple.

Seen from afar, the flower fields are like white clouds floating, making visitors appear to be walking in a sea of clouds.