1. Introduction to Ho Citadel

Ho Citadel (also known as Tay Do Citadel, Tay Giai Citadel, or An Ton Citadel) is located within Vinh Long and Vinh Tien communes in Vinh Loc District, Thanh Hoa Province, approximately 45 kilometers from Thanh Hoa city center.

This historical monument holds exceptional cultural and historical value for Vietnam, directly connected to the military and economic strategies of the Ho Dynasty - a dynasty with a brief existence (1400-1407) yet crucial importance in Vietnamese history.

In 1986, the Ho Citadel site was classified by the Ministry of Culture, Sports and Tourism as a National Monument of special importance to the Vietnamese nation. By 2011, Ho Citadel received UNESCO recognition as a World Cultural Heritage site, contributing significantly to the preservation and international promotion of Vietnamese culture.

Ho Citadel monument was recognized by UNESCO as a World Cultural Heritage site in 2011. (Source: Internet) 

2. Exploring the Historical Formation of Ho Citadel

In 1397, Ho Quy Ly took advantage of the Tran Dynasty's instability to seize power and claim control of the country. During this period, he decided to relocate the capital from Thang Long (Hanoi) to Tay Do (Thanh Hoa), an area that was easier to defend and farther from northern threats such as the Ming Dynasty. The construction of Ho Citadel was part of a strategic plan to protect the nation and strengthen the royal court's authority.

The citadel was built and completed in record time - just three months in 1397 (from the first to third lunar month). In 1400, Ho Quy Ly ascended to the throne, adopting the dynastic name Dai Ngu, and Ho Citadel officially became the capital of the new dynasty.

As the capital of Dai Ngu, Ho Citadel served as a strategic defense layer. Its location near water sources and treacherous terrain helped avoid attacks from the north. The citadel's construction also demonstrated Ho Quy Ly's power and highlighted the Ho Dynasty's stability before domestic and foreign forces.

Ho Citadel was constructed in 1397 in the record time of just three months. (Source: Internet) 

3. What Makes Ho Citadel's Architecture Unique?

Ho Citadel was built on a 155-hectare foundation (core area), while the entire monument complex spans 5,000 hectares. Regarded as Vietnam's "one and only" stone fortress construction, the citadel was built following fundamental principles of terrain, feng shui, and strategic positioning, with rivers and mountains providing natural protection and creating significant military advantages.

The citadel comprises several components: the Inner Citadel, Outer Citadel, Moat System, and Nam Giao Altar. The exterior features stone construction, while the interior primarily consists of earthwork.

3.1. Inner Citadel: Solid Construction with Arched Gate Design and Massive Stone Walls

The entire exterior of the Inner Citadel consists of citadel walls and four main gates: South, North, East, and West. The South Gate serves as the main entrance with three doorways, while the remaining gates have single doorways. The gates feature arched designs with stone blocks carved into grapefruit segment shapes, fitted tightly together to enhance load-bearing capacity.

The wall system and four main gates were constructed from massive monolithic stone blocks, typically measuring around 1.5 meters in length, with some stones reaching up to 6 meters. Each stone block weighs between 10 to 20 tons. Notably, the western wall section features one enormous stone block weighing 26.7 tons.

The entire construction required massive material volumes, including approximately 25,000 cubic meters of stone and nearly 100,000 cubic meters of earth, meticulously excavated and arranged. All stones were stacked tightly together without any binding agents, yet the structure has maintained its integrity for over 600 years - testament to the extraordinary construction techniques of that era.

The southern citadel gate with three majestic and solid doorways. (Source: Internet) 

The citadel gates were built with arched designs to enhance load-bearing capacity. (Source: Internet) 

The citadel wall sections with enormous stone blocks stacked upon each other. (Source: Internet) 

3.2. Moat System: Solid Construction with Rubble Stone and Stone Chips at the Base

The moat system consists of water channels running around the four citadel walls of Ho Citadel, connected to the Buoi River through the southeastern corner of the citadel. This area spans over 90 meters wide, with a moat bottom 52 meters wide and over 6.5 meters deep, gradually widening and sloping toward the surface. During construction, builders used rubble stones and stone chips as foundation material to ensure stability.

Currently, many sections of the moat system have been filled in, but traces remain clearly visible on the northern, eastern, and half of the southern sides of the citadel.

The structure of Ho Citadel's moat system after excavation. (Source: Internet)

3.3. Outer Citadel: Magnificent Outer Perimeter Defense Ring

The Outer Citadel represents the outermost earthen defense ring surrounding Ho Citadel's royal city - a massive defensive structure built in the late 14th century. Today, the Outer Citadel remains intact with an impressive height of approximately 6 meters, featuring a trapezoidal cross-section with a 9.2-meter surface width and a 37-meter base width. The exterior slope stands vertically to prevent enemy intrusion, while the interior features a gradual stepped design with each step measuring 1.5 meters high, with some sections reinforced with gravel and pebbles.

Constructed using various colored clay soils - yellow, gray, or blue-gray mixed with laterite stones - the Outer Citadel was skillfully built following natural terrain, connecting hilltops and curving along the Buoi and Ma Rivers. This structure served not only military defense purposes but also functioned as flood prevention for the entire royal city, demonstrating the exceptional talent and wisdom of ancient Vietnamese in fortress construction arts.

The Outer Citadel at Ho Citadel serves to protect the fortress and prevent flooding. (Source: Internet)

3.4. Nam Giao Altar - The Most Sacred Spiritual Structure of the Ho Dynasty

Nam Giao Altar was constructed in 1402 during the reign of King Ho Han Thuong (Ho Quy Ly's son). Located approximately 2.5 kilometers southeast of Ho Citadel, this site served as the venue for Heaven Worship ceremonies - the most solemn and sacred ritual in the feudal ceremony system, intended to pray for national peace and confirm the dynasty's legitimacy.

The entire altar features multiple ascending levels, narrowing from bottom to top, with its back against Mount Dun and facing south - the direction considered to bring life energy and good fortune. The spirit path leading to the altar's center was paved with polished blue stone slabs, arranged orderly to create a solemn and majestic appearance.

Nam Giao Altar served as the venue for Heaven Worship ceremonies, praying for national peace and prosperity. (Source: Internet) 

3.5. Additional Spaces and Monuments Creating Cultural and Historical Value

1 - Outdoor Exhibition Space: Inaugurated on April 6, 2023, this area introduces and promotes the value of artifacts collected through archaeological excavations within the Inner Citadel area.

• Tay Do Agricultural Culture Space: Recreates the rural life of ancient Thanh Hoa with farming tools such as plows, hoes, water scoops, rice mortars, and household items including wood stoves, dining trays, and dish cabinets.
• Divine Cannon Models and Ho Dynasty Reforms: Including divine cannons, ancient shipbuilding, paper currency reforms, examination system reforms, Nom script promulgation, etc.
• Stone Construction Display Area: Artifacts consisting of stones found along the citadel's base during excavation have been arranged into citadel wall architectural models at the South Gate courtyard.

Outdoor exhibition space for artifacts at Ho Citadel. (Source: Internet) 

Divine cannon models invented during the Ho Dynasty. (Source: Internet)

2 - Supplementary Exhibition House: Displays artifacts related to the existence and development period of the Ho Dynasty, including:

• Architectural Decorative Materials: Roof tiles (lotus bud tiles, leaf-shaped tiles, yin-yang tiles, turtle tiles, ridge tiles, etc.) and artifacts such as mandarin duck statues, balanced leaves, asymmetrical leaves, etc.
• Construction Materials: Primarily stone and brick artifacts used for citadel construction and military defense. Most bricks bear location markings and production sites inscribed in Chinese-Nom characters.
• Military Weapons: Divine cannons and ancient warships represent major weapon inventions during the Ho Dynasty. Additional military weapons include iron arrowheads, stone bullets, iron spearheads, four-sided iron spikes, etc.
• Household Artifacts: Made from glazed ceramics such as bowls, plates, cups, and vessels used in daily life and ceremonies, dating to the late 14th and early 15th centuries.

Bowls and pots used in ancient households. (Source: Internet) 

3 - Adjacent Historical Sites

• Binh Khuong Temple: Located east of Ho Citadel in Dong Mon village, Vinh Long commune, the temple is associated with the legend of Lady Binh Khuong, who died defending her husband's honor.
• Dong Mon Communal House: Located approximately 150 meters from the eastern citadel gate, spanning 5 compartments with red tile roofing and exquisitely carved decorative patterns, embodying the cultural essence of Vietnamese village communal houses.
• Pham Ngoc Tung Ancient House: A 200-year-old ancient house located west of Ho Citadel, built by a Nguyen Dynasty mandarin.
• Tuong Van Pagoda: An ancient pagoda located at the foot of Mount Dun (Don Son), 2.5 kilometers southeast of Ho Citadel. The pagoda was built during the Tran Dynasty; Tuong Van means "auspicious clouds."

Dong Mon Communal House features characteristic architecture of traditional Vietnamese village communal houses. (Source: Internet) 

The name Tuong Van means "auspicious clouds." (Source: Internet) 

4. Important Notes When Visiting Ho Citadel

4.1. Visit Ho Citadel During Cool Weather Periods

Thanh Hoa Province belongs to the North Central region and experiences relatively harsh climate conditions. When visiting Ho Citadel, tourists spend most time outdoors, so the ideal periods to visit are during spring (February to April) or autumn (September to November).

Visitors should avoid summer months (May to August) due to hot weather or months with frequent storms and rain to ensure the most comfortable trip experience.

The ideal time to visit Ho Citadel is during spring or autumn when the weather is cool. (Source: Internet) 

4.2. Choose Appropriate Transportation According to Your Needs

If departing from Hanoi, you can choose:

• Private Motorcycle/Car: Ho Citadel is approximately 140km from Hanoi, equivalent to 2-3 hours of driving. You'll travel via National Highway 1A then National Highway 217 to reach Ho Citadel.
• Coach Bus: You can catch coaches at My Dinh, Giap Bat, or Nuoc Ngam bus stations with companies operating Hanoi - Vinh Loc (Thanh Hoa) routes, with ticket prices ranging from 90,000 - 250,000 VND per person (depending on the bus company). You'll disembark at Vinh Loc bus station, approximately 1.1km from Ho Citadel, and take a motorcycle taxi or use transfer services provided by bus companies to reach the monument.

For distant locations like Ho Chi Minh City, you can choose air travel for maximum time efficiency. Vietnam Airlines currently operates numerous flights to Tho Xuan Airport (Thanh Hoa). You can book flight tickets on the official website www.vietnamairlines.com or through the Vietnam Airlines app to receive reasonable prices and accompanying promotions.

Tho Xuan Airport is approximately 32km from Ho Citadel, so after arriving at the airport, you can travel by taxi or motorcycle to reach the monument.

If you're in Ho Chi Minh City, you can book flight tickets to visit Ho Citadel. (Source: Internet)

4.3. Prepare Appropriate Clothing and Essential Items

Ho Citadel covers a very large area, requiring considerable walking, especially when exploring the Outer Citadel and Nam Giao Altar areas. Therefore, choose comfortable shoes and sandals, preferably flat-soled footwear to prevent foot pain and mobility difficulties.

Additionally, prepare items such as umbrellas, hats, caps, sunglasses, and drinking water, especially on sunny days.

Tourists should prepare items like umbrellas, hats, and caps to facilitate smooth visits. (Source: Internet)

4.4. Don't Just Rush Past the Four Citadel Gates

Ho Citadel represents a unique and massive stone architectural work, symbolizing the history, culture, and military aspects of the Ho Dynasty. Begin your visit from the South Gate - Ho Citadel's majestic main entrance, then walk along the citadel wall sections to appreciate the grandeur and solid construction techniques of ancient builders.

Spend more time in the archaeological excavation area within the Inner Citadel to visualize the ancient palace foundations or stand at the center of the former imperial city, close your eyes, and imagine the court scenes from over 600 years ago during the Ho Dynasty period.

Visit from the South Gate of Ho Citadel along the citadel wall sections to witness the majesty of this construction. (Source: Internet) 

4.5. Listen to Stories from Local People

The construction and completion process of Ho Citadel involves more than just the ancient stone blocks standing majestically in the Vinh Loc fields of Thanh Hoa - this stone citadel also conceals countless stories passed down through generations of local residents.

Therefore, long-time residents living around the monument, vendors selling drinks or souvenirs often serve as "treasure troves" of Ho Citadel stories. Tales about the miraculous three-month construction process, folk legends, anecdotes, or the turbulent life of Ho Quy Ly, etc. A friendly greeting, some openness, and a few conversations can provide fascinating information when visiting this location.

4.6. Visit Small Restaurants in Vinh Loc Town

About 2km from Ho Citadel in Vinh Loc town, you can enjoy many delicious dishes such as: Fresh Vinh Loc goat, taro roots, Bong village rice crackers, Phu Quang sweet soup, street food like mixed rice paper, spicy mango salad, sweet soup, etc.

Vinh Loc's coastal location also offers various seafood options including squid, shrimp, crab, and sea crab, prepared in diverse ways with delicious flavors for tourists.

Phu Quang sweet soup, a specialty of Vinh Loc district. (Source: Internet)

With its solid stone blocks and unique design capable of withstanding enormous pressure, Ho Citadel continues to stand proudly and majestically in Thanh land for over 600 years. For those who love exploring and learning about ancient architectural works and historical dynasties, Ho Citadel represents an ideal choice for travelers.

Currently, Vietnam Airlines operates direct flights to Thanh Hoa from Ho Chi Minh City, with connecting flights from Ho Chi Minh City to various destinations such as Nha Trang, Con Dao, Buon Ma Thuot, etc. Travelers can explore flight options to Thanh Hoa on the official website www.vietnamairlines.com or through the Vietnam Airlines app to book tickets and receive the best promotions.