Xieng Khuang province: This year almost 4,000 people have made the pilgrimage to the infamous Tham Piew Cave in Xieng Khuang province where 374 people taking shelter were killed when a US fighter aircraft bombed the cave 46 years ago during the Indochina War.
Every five years a special ceremony is held to commemorate the massacre, when thousands of people visit the cave to pay their respects to those who died.
Party and state leaders, officials and people from around the country travel to the province to attend the ceremonies.
This year the visitors included the participants of a convoy of 136 vehicles that had travelled up from Vientiane and stopped off at the cave on Saturday. The convoy was organised by the Ministry of Information, Culture and Tourism.
A tour guide who works at the cave, Mr Kongsy Somsanith, said most people who visit this notorious site are students from colleges and universities in Vientiane and Champassak and Luang Prabang provinces.
Last year more than 4,000 people visited the cave for a grim reminder of the horrors of war.
American attacks in Xieng Khuang province began in 1964. It was in the late afternoon of November 24, 1968, th at Tham Piew Cave was hit.
The US aircraft launched four missiles at the cave. The first and second missed the target but the third and fourth found their way into the cave and killed all 374 people inside.
All of those who died in the attack are buried in front of the cave.
Tham Piew Cave is located in Boumlong village in Kham district, about 60km east of the provincial capital of Phonsavanh.
The cave is one of several sites in Xieng Khuang attracting an increasing number of visitors, with about 48,000 foreign nationals travelling to the province last year. The Plain of Jars, Keng Mountain, and Kha and Ka waterfalls are also popular with foreign visitors.
In 2013, Xieng Khuang generated revenue of about US$5 million from over 43,000 foreign visitors.
The number of tourist arrivals across the country is growing every year with over 3.3 million people coming to Laos last year, a 22 percent increase on 2011.