That Dam Stupa, located in the middle of a roundabout near Talat Sao Market, is believed to be around 500 years old. The name That Dam means "Black Stupa" in Lao, a reference to its current appearance. It is not only black in color but also has grass growing on top.
The stupa, a Buddhist structure built in the 16th century, was once covered in pure gold. However, during the Siamese-Lao War in the 1820s, the gold was stolen and taken to Siam—modern-day Thailand—leaving behind the Black Stupa we see today.
In general, stupas are built to house Buddhist relics, such as the remains of monks or kings. What lies inside That Dam Stupa remains unknown, but according to legend, locals believe a seven-headed dragon still sleeps beneath it and will awaken whenever Vientiane is in danger. Many Lao people say it protected the city during the Siamese invasion of 1827 and other critical moments in history.
Today, although in a state of disrepair, the stupa’s historical and cultural significance remains strong. Many Lao people still consider it a powerful symbol of the city's spiritual protection.