The most highly revered stupa in Loei Province, this whitewashed Lao-style chedi stands 20m high and was built in 1560–63 on what was then the Thai–Lao border as a gesture of unity between the Lao kingdom of Wiang Chan (Vientiane) and the Thai kingdom of Ayuthaya in their resistance against the Burmese. You can't wear shoes or the colour red, or carry food or open umbrellas around the stupa. Down below is a modest museum with random artefacts donated by locals.
Despite the use of the name 'Phra That', there are no Buddha relics in the stupa.