The king also erected the imposing Lan Na style "that", or stupa, that graces the ground in back of the sim. This stupa-prasat style has a tiered square base surmounted by the stupa with square, octagonal and round tiers above. The northern Thai influence can be seen in the golden umbrellas at the peak of the stupa and in many other places in the wat.
The wonderful sweeping stair and entryway from Thanon Chao Fa Ngum Road and its silver colored seven-headed naga is reminiscent of the more colorful and elaborated longer stairway at Wat Doi Suthep in Chiang Mai, Thailand. The adjoining wat to the northeast, Wat Ho Xiang, has similar decorative design flanking its stairway.
The present sim, or vihan, was rebuilt between 1907 and 1910 by Chao Maha Oupahat boun Kong to replace the one that collapsed during a typhoon that struck during evening prayers in April 1900. Many lost their lives in the tragic event that destroyed many other buildings of the wat. The sim, in Luang Prabang style, was rebuilt in 1910, and then restored beginning in 1963. More recent work on it (from 1991) has created a most attractive and ornamented façade with decorated rosette columns. There are interesting relief murals in its frontal portico and decorations depict the legends of King Thao Sithoanh and the Nang Manola, the kinnari (divine half-woman/half-bird reputed for its frolicsome kindness) in addition to stories from the Phra lak phra lam (the Ramayana). The popular Laotian legend is of Khmer origin and is very popular. The sim has a double-tiered roof with a magnificent fifteen segmented "Dok So Fa" (or nhot so fa), a metallic ornamentation at the center of the roof beam. The Dok So Fa symbolizes the universe and Mount Meru and is found on most Laotian sims. This particular Dok So Fa consists of a series of pagoda forms.
There are statues of the Earth Goddess, wringing water from her hair, that recall the story when the Buddha was threatened by the army of evil spirits and called on her. The water, accumulated from the meritorious deeds performed in his previous lives, drowned the entire Maran army.
Wat That had long served as one of the more significant wats in Luang Prabang. During the Laotian New Year, leaders of traditionally important Luang Prabang wats (Mai, Xieng Thong, Aham and Vixun) had solemnly visited it by palaquin. It still remains an important element of the religious structure of the city. Within the confines of the wat also are the ashes of the revered Prince Phetsarath (believed by many to have had magically invincible powers as a half-deity, half-royal khon kong), who declared Laos independent after the Japanese surrender in 1945, and Prince Souvanna Phouma, his younger half-brother, who served as prime minister and sought to retain Lao independence in negotiations with the Pathet Lao.
Text by Robert D. Fiala, Concordia University, Nebraska, USA