Vieng Xai Cave City

Pathet Laos Caves

Useful Information

Location: Vieng Xai, Hua Pan, northeast Laos. At Nam Meo, between Xam Neua and the Lao-Vietnamese border. Houaphan Province, Vieng Xai District.
Fee: Adults KIP 9,000.
Classification: SubterraneaCave House
Light: LightIncandescent Electric Light System
Guided tours: D=2 h.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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1955 Lao communist party formed in Sam Nua.
1963 shadow government installed underground.
1964 start of the undeclared secret war against the communists in Laos by America.
1973 end of secret war.
1975 the King and his wife are banished here until their reported death a few years ago.
1990s opend for occasional backpackers.


We were not sure how to classify this cave city, as Vieng Xai is located in a limestone region, and there are numerous karst caves. But over decades the city has be used by the communist revolutionaries, the Pathet Lao, as hideout, headquarters and retreat. They built hundreds of underground houses, using the soft limestone to dig almost 200 m into the rock, or by enlarging natural caves. The area was bombarded by the United States with approximately two tons of bombs per capita.

There are 800 caves in the area of Vieng Xai, seven of them are open to the public now. Those seven caves were the headquarters for the masterminds of the Pathet Lao. They are well-preserved, showing their save but spartan life. The tours show those cave during two hours.

The first cave, Tham Khamtay (Defense Minister Cave) is the war-time dug out of Khamtay Siphandone, the country's sitting president. The unimposing entrance leads to a narrow whitewashed corridor that winds past a series of meeting rooms with wooden walls. It finally arrives at Khamtay Siphandone's bedroom and that of his nephew. Between the two bedrooms is a concrete bunker called emergency room. It was built in case of chemical warfare and outfitted with a Soviet-grade, wooden oxygen pump. It was sealed with a 2-inch-thick, airtight submarine door. A staircase provides access to a large lower cave, which cuts trough the limestone hill and is predominantly natural. This lower section of Tham Khamtay is called Tham Xam Lot and it has a large chamber fitted with an underground theatre. Tham Khamtay-Tham Xam Lot is by far the longest cave accessible to tourists at about 900 m of length. Tham Xam Lot is also called Soldiers' cave, as it was home to 2,000 soldiers during the war. Many remains of the natural caves can be seen, like stalactites and stalagmites, which were incorporated into the structure. There was little space and little privacy, but at least the cave was electricly lit since 1971 and there was a mini water reservoir for bathing. Unfortunately half of the caves gets flooded at the peak of the rainy season.

The third stop is the Royal pad, a pink house belonging to Prince Souphanouvoung. He was the youngest of three influential brothers who dethroned the king, their uncle who was pro-French, in 1945. They set up the first "Free Lao" government. Souphanouvoung was called the Red Prince, as he was influenced early by the Viet Minh. In 1950 he founded the Pathet Lao together with the men who later formed the party's inner circle. He lived in this villa, with tennis court, swimming pool, and a Mediterranean garden with fuchsia plants and pomelo trees. The house has a small dugout cave, Tham Souphanouvong (Red Prince Cave) with living quarters for an in-house medical staff and a patio-like kitchen area.

The fourth cave belonged to Kaysone Phom Vihane, the driving force behind the Pathet Lao, who is regarded as the country's Uncle Ho. He is said to have directed the Socialist revolution. From 1975 to his death in 1992 he led Laos as president. His cave Tham Kaysone (Leader Cave) served as the meeting point and living quarter for the Politburo, with six members sleeping in the front room.

Nouthak Phovan Savane, Kaysone's right-hand man, lived on the other side of the road. He had a one-bedroom cave with its own oxygen-machine. The cave is reflecting the ascetic lifestyle of its owner.

A trip to Vieng Xai is difficult and requires long bus rides either from Luang Prabang or Phonsavanh. There are regular bus connections from the provincial capital Xam Neua to Vieng Xai. There are several guesthouses in the village as well as a recently re-opened governmental hotel. Restaurants are available in the village. The Laos government only recently has made the karst areas in Houaphan accessible for foreigners. Nevertheless they attract up to 200 visitors per month with a growing number. The touristic infrastructure is limited but still existing. A guide service starts at the Vieng Xai tourist centre.

Vieng Xai is a tower karst formed in Upper Triassic limestone. As typical for such a late stage in karstification, there are many trough caves. Underground river courses with huge and beautifully decorated cave passages are abundant, examples of which are Tham Nam Long (4,981 m in length), Tham Nam (3,008 m), and Tham Ma Liong (1,565 m). The caves - including the tourist caves described above - were surveyed by the Northern Lao-European Cave Project during its expeditions in 2007 and 2008. A comprehensive report including the cave maps was published in English language in the series Berliner Höhlenkundliche Berichte (vol. 32).