HCMC Museum – A Secret Viet Cong Commando Arms Cache

When the Tet Offensive erupted in the early hours of January 31, 1968, Saigon became the epicentre of a shock campaign that brought the war into the very heart of South Vietnam’s capital. Behind the sudden, coordinated attacks on key targets — including the nearby Independence Palace — lay years of careful planning, covert operations, and hidden networks embedded within the city itself. One of the most remarkable remnants of that covert preparation survives today in an unassuming house in District 3, where a secret Viet Cong arms cache once armed the commandos who set out to strike during Tet — now preserved as a museum that reveals the extraordinary ingenuity and risks behind the offensive.

In a bustling alley off Nguyễn Đình Chiểu Street in District 3 stands house number 287/70. Beneath its modest exterior—indistinguishable from other working-class homes—lies a secret bunker that once stored nearly two tons of weapons for the National Liberation Front’s Saigon Commando (Biệt Động Sài Gòn) Team 5.

Inside, an elaborate underground system concealed a vast arms cache, including 350 kilograms of TNT, C4 explosives, 15 AK-47 rifles, B40 launchers, hand grenades, and around 3,000 rounds of ammunition. Even more remarkable was its location in the heart of the city, near the Independence Palace. Owned by an interior decorator who was well regarded by members of President Nguyễn Văn Thiệu’s administration, the cache’s construction and preparation was years in the making and all done in complete secrecy.

Trần Văn Lai (also known as Nam Lai) was a covert Communist agent from Thái Bình Province whose commitment to the revolution predated American involvement in South Vietnam. Under the alias Mai Hồng Quế, he moved to Saigon posing as an interior decorator. He soon gained a reputation as a government contractor whose style and taste curried favour with the regime.

*An informal portrait of Trần Văn Lai during his time as a military administrator in Saigon in the early days post liberation in 1975. Image restored by Julian Tennant.*

By 1966, Lai and Thiệp had acquired three houses on Nguyễn Đình Chiểu Street to support preparations for coordinated attacks on key targets in Saigon, including the Independence Palace and the US Embassy.

Construction of the weapons cache at 287/70 began under the pretext of digging a septic pit and took seven months to complete. Soil was hidden in crates and transported at night to avoid detection.

The bunker entrance, located near the staircase, was cleverly disguised within the floor, with a hidden latch lifted by a small ring. Measuring approximately 60 by 40 centimetres, it was nearly impossible to detect. Below, the bunker extended over 8 metres long, 2 metres wide, and 2.5 metres deep. It also featured circular hatches connected to drainage pipes that served as emergency escape routes.

Weapons were smuggled into the house using ingenious methods—hidden inside hollowed wooden planks, flower baskets, and fruit crates. At the time, it was considered the largest and most secure weapons bunker in central Saigon.

Citroën 2CV Fourgonnette van, supposedly used to transport the weapons to the cache.

Entry to the cellar housing most of the weapons is via a trapdoor hidden near the staircase.

Weapons were hidden in a variety of places including hollowed this hollowed out section of a table bench top.

Bamboo-woven mat used to conceal the weapons for the attack on the Independence Palace, 1968

The *secret cellar housing the Viet Cong arms cache at 287/70 Nguyễn Đình Chiểu* cellar Over 8m long, 2m wide, and 2.5m deep, it included an escape hatch (the round cavity on the far wall) which connected to the drainage system for an emergency exit.

Motorcycle used by the 5th Commando Team to attack the Independence Palace during the Tet holiday, 1968.

Scars of Tet 1968. Bullet and shrapnel holes on the exterior gate of the house.

Tết Nguyên Đán – 31 January 1968 and Aftermath

In the early hours of 31 January 1968—the second day of the Lunar New Year—15 members of Team 5 gathered here to collect their weapons before departing in three cars and a motorbike toward the Independence Palace as part of the Tet Offensive.

The attack failed, and suspicion soon fell on Lai. The vehicles he frequently used drew attention, and his cover was blown. Once a respected figure with easy access to the Independence Palace, he became a wanted man overnight, with a substantial bounty placed on his capture. His assets were seized, and a citywide manhunt began.

Forced into hiding, Lai moved constantly and rarely saw his family. He was eventually captured and sent to Con Dao Island, but his captors failed to recognise his true identity. Despite torture, he revealed nothing and was ultimately released in a weakened state. By then, the house had been taken over by American forces, who—remarkably—never discovered the hidden bunker.

After the fall of Saigon and reunification in 1975, Lai resumed working for the new Communist regime as part of the B.12 Forward Unit of the Saigon-Gia Dinh City Command, where he was initially tasked with hunting down and seizing the property of former officials, military officers and ‘enemies’ of the new regime. He also took on the role of Head of the Management Board of the Tam Da Shopping Centre, largest commercial centre in Saigon at the time. In 1977, he transferred to the War Summary Department of the City Command until retirement in 1981. Trần Văn Lai died in 2002. His wife, Thiệp, and son, Trần Vũ Bình began working to preserve his legacy, taking ownership of the properties once associated with him. The home at 287/70 was eventually converted into a museum and coffee shop (Cà Phê Đỗ Phủ). It was recognised as a National Historical and Cultural Monument in 1988.

*Portrait of Trần Văn Lai wearing one of the uniforms that is on display in the museum.*

Saigon Commando Secret Weapons Bunker

287/70 Nguyễn Đình Chiểu,
District 3
Ho Chi Minh City
Vietnam

Open Everyday 07:30 – 11:30 / 13:00 – 17:00

Entry is free

The 1968 Tet Offensive

The Tet Offensive is widely regarded as the turning point in the Vietnam War, marking the moment when the allies effectively lost—even though they held a position of relative military strength at the time.

In late 1967, allied intelligence detected signs of a major communist offensive planned for the Lunar New Year (Tet), but lacked details about the targets or strategy. Frustrated by the ongoing stalemate, North Vietnam decided to launch a large-scale attack aimed at achieving a decisive victory. Key points across the south came under attack, but central to their plan was the capture of Saigon within two weeks, with the expectation that a general uprising would follow, resulting in the city’s fall.

Although the Viet Cong announced a ceasefire for the holiday, allied forces remained cautious. They implemented a limited truce while keeping troops on alert, especially in key urban areas such as Saigon. Preparations led by Frederick Weyand, the U.S. commander in the III Corps Tactical Zone, ensured that only half of the South Vietnamese forces were permitted to stand down, while American and other allied troops were fully alert and positioned to respond to any attacks.

At 3:00 a.m. on 30 January 1968, communist forces launched coordinated attacks on cities across South Vietnam. Saigon was the primary target, with assaults on government buildings, military bases, and the U.S. Embassy. The timing during Tet celebrations allowed the attackers to achieve surprise, as firecrackers masked the sound of gunfire.

Despite the scale and intensity of the offensive, communist forces failed to achieve their main objectives. By early February, they began withdrawing from major positions, though fighting in Saigon continued into March. The city suffered heavy damage, particularly in areas such as Cholon, where many civilians were killed.

Militarily, the offensive was a severe defeat for the communists: around 45,000 of their fighters were killed across South Vietnam, compared to roughly 6,000 allied deaths, and much of their southern infrastructure was destroyed. However, the psychological and political impact told a very different story.

The fact that such a large-scale attack was possible contradicted repeated claims by U.S. officials that victory was near. Media coverage—especially of the assault on the U.S. Embassy—shocked the public and fueled doubt about the war’s progress.

This shift in public opinion forced a major policy change. President Lyndon B. Johnson refused requests for more troops, scaled back bombing in North Vietnam, and chose not to seek re-election in 1968—an implicit acknowledgment that the war strategy had failed.

In the end, although the Tet Offensive was a military disaster for the communists, it became a major propaganda victory, fundamentally altering perceptions of the war.