Boon Tat Luang, celebrated in November, is the biggest national holiday in Laos. Boon Tat Luang is more of a Lao Buddhist celebration rather than a Buddhist event. Tat Luang translates to mean Great Sacred Stupa . Tat comes from a Pali-Sanskrit word dhatu which means a component of. Tat refers to a spiral or dome-like structure that commemorates the Buddha's life. This can be seen at the tip of Tat Luang. This stupa is located in Vientiane. All government offices close, and school children are off to celebrate. In the U.S., Boon Tat Luang is celebrated simply by attending the temple. The celebrations in the U.S. does not come close to the festivities in Laos.

According to legends, Tat Luang was constructed by Indian missionaries to house a breastbone of the Buddha around 3rd century BC. It is believed that the structure that is standing today bears no resemblance to the legendary stupa, and there has been no proof that a breastbone actually resides in the monument. However, archaeological digs have shown that Tat Luang might have been constructed by the Khmer between 11th and 13th centuries AD.

The structure that stands today was constructed in the mid 16th century by a king of what is present day Laos, King Sethathirat. A statue of the king now stands in front of the stupa. In subsequent years, 4 wats were built around the stupa. It has been recorded that the top of the stupa was once covered with gold. Over the centuries, Tat Luang endured many foreign invasions. It was left in overgrown vegetation until the 19th century when it was rediscovered by a French explore. Tat Luang as it appears today was restored in the 20th century.