Located just 24km away from the city center, the ancient citadel of Co Loa stands out as a popular weekend getaway for many young travelers in Hanoi. To visit Co Loa Citadel, you can take the old National Highway 1A towards milestone 10, known as Duong Bridge. After crossing the bridge, you'll reach Yen Vien town, where you'll turn left onto National Highway 3 and travel an additional 5km to reach the junction leading to Co Loa.
If you prefer traveling by bus, you can catch Route 46 from the My Dinh area or Routes 15 and 17 from the Long Bien transfer station.
2. Geographic and Historical Significance of Co Loa Citadel
From a geographical perspective, the location of Co Loa Citadel holds significant importance. It is situated at the confluence of two vital rivers near Co Loa, marking the second apex of the Red River Delta, currently within the administrative boundaries of Dong Anh district, Hanoi.
Standing as the oldest and most imposing fortress in Vietnam, Co Loa Citadel boasts a unique and monumental structure unparalleled among the country's ancient citadels. From its inception in the 3rd century BCE as the royal capital of Au Lac to its role as the seat of power for King Ngo Quyen in the 10th century CE, Co Loa has been a symbol of Vietnam's enduring legacy. Today, it stands as a testament to the nation's resilience and cultural pride, beckoning travelers and history enthusiasts alike to explore its storied grounds.
The architecture of Co Loa Citadel reflects a continuous evolution of Vietnam's civilization, tracing its roots from ancient times to the pinnacle of Dong Son culture. These archaeological sites provide invaluable insights into the development of the Vietnamese people, showcasing a rich tapestry of history that spans millennia.
Through archaeological excavations, researchers have unearthed a wealth of artifacts that illuminate Vietnam's journey from its earliest origins to the zenith of Dong Son culture. This prehistoric civilization, centered around the Red River, laid the foundation for Vietnam's cultural identity and enduring legacy.
Cổ Loa Citadel, also known as Loa Citadel, was constructed in a spiral pattern, hence its name. Legend has it that there were originally 9 concentric spiral rings of citadel walls, but only 3 remain to this day. The Inner Citadel has a circumference of 1600m, while the Outer Citadel spans 15km in circumference. It has a serpentine shape and comprises numerous unique architectural structures such as the Jade Well, the Cao Lỗ Statue, and the Mị Châu Temple.
The Outer Citadel: With a circumference of approximately 8km, the Outer Citadel was constructed using the technique of digging and filling moats and building walls adjacent to each other. The ancient ramparts range from 4-5m in height, with some sections reaching 8-12m. The estimated total volume of earth used is 2.3 million m3.
The Central Citadel: It has a circumference of around 6.5km and shares a similar structure to the Outer Citadel but is narrower and more robust.
The Inner Citadel: Covering an area of approximately 2km2, it served as the residence of King An Dương Vương along with his concubines, courtiers, and officials. Today, it is also the site of the royal temple and gathers historical architectural monuments related to the Cổ Loa Citadel complex.
Discover the majestic heritage at Co Loa Ancient Citadel
Ancestral shrine of King An Duong Vuong
The An Duong Vuong Temple, also known as the Upper Temple, sits at the heart of the Inner Citadel, once the abode of King Thuc Phan. Positioned atop a dragon-shaped mound, flanked by verdant forests, with two circular pits resembling dragon eyes below. Just in front lies a vast lake, housing the legendary Ngoc Well—where Trong Thuy submerged himself in the mythic narrative.
Within the temple, there are remnants of ancient artifacts such as the bronze statue of An Duong Vuong, two pink-and-white horses, various bronze, porcelain, wooden, and fabric items. Outside the gate stand two stone dragons, their bodies intricately coiled, with finely carved features reflecting the architectural style of the Le dynasty.
The Royal Court Pavilion - Co Loa Citadel
Constructed on the foundation of the ancient royal palace, this pavilion was relocated and reconstructed in the late 18th century on land traditionally believed to be where King Thuc Phan established his court. At the center of the pavilion is a decorated gate adorned with the four sacred creatures (dragon, unicorn, turtle, phoenix) and the four noble plants (peach, apricot, bamboo, plum), intricately carved and gilded. The pavilion boasts sturdy architecture and houses numerous archaeological relics dating back thousands of years, of immense historical value.
The Enigmatic Shrine
Locals often refer to this place as the Mị Châu Tomb, nestled just behind a thousand-year-old banyan tree casting its cool shade over a vast courtyard, its roots splitting into a makeshift doorway inviting nature's embrace into the shrine. Here lies a statue known as the Mỵ Châu statue – a natural rock formation shaped like a headless figure. Legend has it that after Mỵ Châu's death, she transformed into a large rock which drifted to the Forbidden Sands beach, east of the ancient city of Cổ Loa. As the people in the city carried the hammock containing the rock back to the banyan tree, the hammock broke, and the rock fell, prompting the establishment of a shrine right on the spot. The shrine walls bear an engraved Han script poem by poet Chu Mạnh Trinh.

Shrine of Mỵ Châu (photo collection)
The Sacred Cao Lỗ Temple
Travelers staying outside the city center can book accommodations in Dong Anh for convenient transportation, such as:
Co Loa Citadel is not just a historical relic witnessing the changes and developments of our country day by day. It is also a symbol for the nation, for the Vietnamese people with the beautiful traditional values, closely associated with the nation-building and nation-preserving stories from ancient times. Therefore, come once to Co Loa, to relive the glorious history as well as to love more deeply the culture and roots of the nation.