The Sao Mai Ancient Artillery Site, located on Big Mountain (Núi Lớn) in Vung Tau, is considered the largest and most important artillery fortress built in Indochina during the French colonial period. Constructed between 1895 and 1905, this massive military structure formed one of the three key coastal defense points protecting the maritime gateway to Saigon – Đồng Nai.
With six giant cannons, fortified bunkers, and an extensive trench system, Sao Mai Battery was officially recognized as a National Historical Monument in 1993. Today, it stands as both a priceless heritage site and an unforgettable destination for travelers interested in military history and adventure tourism.
Historical Background – The French Coastal Defense System
To secure the strategic sea route leading to Saigon, the French constructed a large defensive network across Vung Tau in the late 19th century. The system included:
- Cầu Đá Battery
- Sao Mai Battery – Big Mountain
- Tao Phùng Battery – Small Mountain
Among them, Sao Mai was the largest and most heavily fortified. Built at 100 meters above sea level, it offered a commanding view over the East Sea and the shipping lanes entering Vung Tau – Cần Giờ – Saigon.
The site originally featured six massive coastal guns, each weighing 15 tons, mounted on circular rotating platforms allowing a full 360-degree firing range.
Architecture and Structure of Sao Mai Artillery Site
Constructed entirely by hand over 15 years, the fortress required tremendous labor: carving into the mountain, transporting artillery pieces, digging tunnels, and building bunkers.
Key components of the artillery site include:
- Six coastal guns, mounted on 3-meter round platforms
- Rotating gun bases enabling 360° movement
- Eight underground bunkers for soldiers and ammunition
- A trench system stretching 102 meters
- Communication tunnels and protective fortifications
All cannons face the sea, ready to control any approaching vessel and protect the entrance to Saigon during wartime.
Torpedo Bunker – A Japanese WWII Legacy
In addition to the French-built artillery site, Big Mountain also preserves two torpedo bunkers constructed by the Japanese army in 1944 during World War II.
Highlights of the torpedo bunker complex:
- Located about 200 meters west of Sao Mai Battery
- Thick stone-and-cement walls up to 1 meter
- Vaulted ceilings, 7 meters high
- Two large entrances, each 20 meters wide
- Internal U-shaped layout designed for storing naval mines and torpedoes
During the war, the bunkers held explosive devices used to block Allied naval forces entering the Vung Tau – Cần Giờ area. After Japan’s surrender, the Viet Minh secretly retrieved torpedoes from these bunkers to supply the resistance movement.
Visiting Sao Mai Artillery Site – What to Expect
Getting there
Visitors follow Alley 444, Tran Phu Street, then drive up a narrow, winding mountain road. Though steep in places, the journey is scenic and rewarding, with one side facing the cliffs and the other offering a sweeping view of the sea.
At the top
You can enjoy:
- A panoramic view over Front Beach and the Vung Tau coastline
- Crisp mountain air and peaceful natural surroundings
- Impressive colonial-era artillery structures
- Hidden tunnels, military bunkers, and torpedo storage sites
This is a favorite spot for history lovers, photographers, trekkers, and anyone seeking quiet moments above the city.
Opening Hours, Fees & Travel Tips
Opening hours: 8:00 AM – 5:00 PM daily
Entrance fee: Free of charge
Tips for visitors:
- Wear comfortable shoes and bring water
- Roads can be steep; take your time
- Best visited in the morning or late afternoon
- Limited tourist services available—plan ahead
Cultural & Historical Value
Visiting the Sao Mai Ancient Artillery Site is more than a sightseeing trip—it is a journey back into the turbulent history of Vung Tau. Here, visitors can:
- Learn about French and Japanese military strategies
- Explore real colonial-era cannons and wartime bunkers
- Understand how local resistance forces utilized captured weapons
- Appreciate the perseverance and sacrifices of past generations
Combined with spectacular natural scenery, the site represents an exceptional blend of history, nature, and military heritage.
Whether you are passionate about history, fascinated by military architecture, or simply love exploring hidden gems, the Sao Mai Ancient Artillery Site on Big Mountain – Vung Tau is a must-visit destination.
Standing among giant cannons, mountain winds, and scenic ocean views, you’ll feel the powerful connection between nature, history, and human resilience—an experience only found in Vung Tau.
