The Flamboyant Festival kicked off on June 9/ night with a colourful parade involving thousands of residents and tourists, artists and performers.
Floats were decorated with the red blossoms while people dressed up in eye-catching red costumes.
A contest for the "best red costume" brought many smiles at the opening night, which also featured a fireworks display.
Many street performances highlighted the beauty of the city, especially the mass choir of 1,000 people which performed the city "anthem" Thanh Pho Hoa Phuong Do (The City of Red Flamboyant) by songwriter Luong Vinh.
A pageant entitled Flamboyant Beauty, a dragon dancing contest, painting and photo exhibitions with a flamboyant theme and installation art performances were popular.
Hundreds of people joined a bicycle parade along the main road where 4,000 flamboyant trees grow, connecting the city's centre with Do Son beach.
The city also launched a walking street and a night market to mark the occasion.
Visitors were impressed by calligraphy works depicting the word "phuong" (flamboyant) by artist Le Thien Ly, who has had the idea since last year to support the Flamboyant Festival. He drew 20 22cmx34cm calligraphy paintings every day, taking more than three months to complete the works.
The festival is an activity to kick off National Tourism Year 2013, which highlights tourism in the Red River Delta region and promotes the city among tourists and investors.
Local authorities expect it will become a "trademark" cultural and tourism product.
The Royal Poinciana is consistently voted among the five most beautiful flowering trees in the world. It is also known by the names Gulmohar, Peacock Flower and Flame of the Forest.