That Pathum, “Stupa of the Great Lotus,” is a large, Singhalese-style stupa commissioned by Queen Phan Tew Xieng in 1514. Standing at 35 meters tall, it is the only stupa of its kind in all of Laos.

The stupa, also known as That Makmo—meaning “Watermelon Stupa”—earned its nickname because the dome topping resembles a giant watermelon. It was constructed to cover Ning Xua pond.

In 1917, the stupa collapsed after being struck by lightning. In the rubble, a crypt was discovered containing Buddha images made from bronze, iron, wood, crystal, and gold, dating back to the 15th and 16th centuries.

The stupa was rebuilt in 1932. Some of these precious images were returned to the crypt inside, while others were housed in the National Museum.