Walking along the tree-lined streets of Hanoi or Saigon, one easily notices faded yellow patches, red tiled roofs, arched doorways, and graceful columns. These are the legacies of over half a century of French presence, a period that both imposed French influence and laid the first foundations for modern Vietnamese architecture.

The beginnings of Western architecture in Vietnam were not magnificent buildings, but defensive structures. In 1790, the French engineer Victor Olivier de Puymanel, at the invitation of Nguyen Anh, designed the Saigon Citadel based on the Vauban model – a type of military fortress common in Europe in the 17th century. From there, this model spread to Hue, Bac Ninh, Nam Dinh, and Hanoi, marking the beginning of the introduction of European construction techniques. When the French occupied Tonkin, the citadels were gradually replaced by a system of churches, symbols of their new power.

In 1880, the Notre Dame Cathedral in Saigon was completed with red Marseille bricks, boasting a Gothic-Romanesque style. Four years later, in the heart of Thang Long (Hanoi), the Hanoi Cathedral rose after the French razed the magnificent Bao Thien Pagoda, a subtle message that the West was gradually replacing the East, and Christianity was gradually replacing Buddhism. These early structures were not only places of worship, but also declarations of a civilization that considered itself "civilizing."

Following the Patenôtre Treaty, Vietnam officially became a colony. Major cities were re-planned according to the French model: straight streets, squares, government buildings, and gardens. Hanoi was chosen as the capital of Indochina, and Saigon as the "Pearl of the Far East." The French built the Governor-General's Palace, the Courthouse, the Treasury, and the Post Office, all featuring neoclassical architecture with columns, Mansard roofs, and yellow plaster walls. Along Trang Tien and Hang Khay streets, small villas interspersed among the administrative buildings created the appearance of "Western Hanoi." In Saigon, the Governor's Palace (now the City People's Committee), completed in 1908, had an elaborately decorated facade, relief sculptures, and ornate wrought iron railings, creating a "magnificent picture of power."

Around the same time, the Hanoi Opera House (1901–1911), modeled after the Opéra Garnier in Paris, became a social hub for the French elite. Concerts and balls held there marked the beginning of modern urban life in Indochina. The Doumer Bridge, now the Long Bien Bridge, designed by Daydé & Pillé, was the first steel bridge to cross the Red River, connecting the industrial and administrative banks. And Dong Xuan Market, with its steel roof and natural ventilation system, demonstrated the first efforts of the French to adapt to the tropical climate.

By 1910, Hanoi and Saigon had taken on a distinctly European appearance. However, the cities remained divided: the "Western quarter" for the French, and the "Vietnamese quarter" for the native population—an invisible boundary reflecting the colonial social structure.

The period of World War I saw a decline in new construction, but the idea that "architecture is a political tool" was established. In Hanoi, Hoa Lo Prison was situated next to the Palace of Justice, a convenient arrangement that also symbolized ruling power. The ancient citadel was demolished to make way for a new administrative area, and Bao An Pagoda was razed to make way for the Governor-General's Palace.

In Saigon, three landmarks—Notre Dame Cathedral, the Governor's Palace, and the City Theatre—formed a central triangle where power, culture, and religion intersected. These buildings were not only administrative centers but also "stages for French civilization" in a remote tropical region.

After a long period of rule, the French government was forced to "soften" its style to appease rising nationalist sentiment. Architect Ernest Hébrard, sent to Indochina in 1921, proposed a "hybrid architectural language" based on French structural systems but incorporating tiled roofs, corbels, and decorative details inspired by Vietnamese temples and pagodas. The University of Indochina, now Hanoi University, is a prime example. Hébrard replaced the Western-style tower with a multi-roofed square pavilion, creating a distinctly "Indochinese" look. Following this style, the Louis Finot Museum (now the National Museum of History) and the Saigon Museum (now the Ho Chi Minh City Museum of History) combined multi-layered tiled roofs, curved eaves, and ventilation shutters. Although more decorative than functional, these structures marked the beginning of the French attempt to integrate their architecture with local aesthetics.

Some buildings from this period also demonstrated technological advancements, such as the Pasteur Institute in Hanoi and the Indochina Finance Department (now the Ministry of Foreign Affairs), which applied natural ventilation, deep eaves, and proper building orientation—features rarely seen in colonial architecture before that.

From 1925–1930, Hanoi entered a period of vibrant construction. The Bank of Indochina, the Far East School of Archaeology, and Bach Mai Hospital were successively established, combining modernity with local spirit, paving the way for a distinctive Indochinese style.

In the 1930s, reinforced concrete became a symbol of the era. The Hennebique frame system was widely applied, allowing buildings to reach greater heights and span larger distances. The Bank of Indochina in Hanoi, with its flat roof, thick walls, and washed stone facade, marked the end of the ornate neoclassical era, ushering in a simpler and more sustainable modern architectural period. The emergence of this new material led to the rise of a class of Vietnamese engineers, contractors, and architects. In 1924, the Indochina School of Fine Arts opened its Architecture department – ​​training the first generation of Vietnamese architects: Nguyen Cao Luyen, Hoang Nhu Tiep, Nguyen Gia Duc, Vo Duc Dien… They studied the Beaux-Arts school of France but began to seek their own language, simpler and more accessible.

The villas on Nguyen Du Street, Thien Quang Street, or the row of houses on Tran Hung Dao Street with their deep eaves, wooden shutters, and ornate railings were the first experiments in the localization of modern architecture.

By the late 1930s, nationalist sentiment was rising among intellectuals. The 1937 student strike at the Indochina School of Fine Arts, protesting the discrimination of the French director, marked a turning point in this spirit: Vietnamese people wanted to design and shape their own spaces.

By 1945, when the flag of independence was raised, a long chapter in architectural history closed. The French left behind a legacy in Vietnam that was both magnificent and contradictory: straight avenues, theaters, iron bridges, churches – but also a harsh social stratification. The "Western quarter" was spacious and green; the "Vietnamese quarter" was cramped and impoverished. Building regulations for the indigenous quarter allowed a density of up to 100%, while the European quarter only allowed 20%. Behind the urban order lay inequality deeply ingrained in every brick. In the countryside, temples and pagodas declined, while Catholic churches rose up like fortresses of the new faith. However, it was on these construction sites that Vietnamese workers learned concrete construction techniques, planning, design… knowledge that later became the foundation of modern Vietnamese architecture.

Looking back, more than half a century of colonial rule not only left behind buildings but also sparked a process of self-awareness. If the initial phase was one of imposition, with Mansard roofs, Doric columns, and Gothic bell towers as symbols of power, the latter half was a period of adaptation and fusion. From within the gaps of the colonial system, the Vietnamese began to learn, then innovate, and finally find their own voice.

Today, strolling among structures like the Grand Theatre, the Saigon Central Post Office, or the History Museum, one not only sees the classical French beauty but also recognizes traces of local character in the curved tiled roofs, shutters, and layers of moss. They bear witness to a long journey: from imposition to localization, from powerful concrete to the breath of Vietnam – where architecture becomes a mirror reflecting history and national identity.