Wat Chalong Temple is most revered for the sacred relic that is kept here, a fragment of a bone of the Buddha. The relic that is named Phra Borom Sareerikatat is kept inside a glass case on top of the 60 meters high Phra Mahathat Chedi. It was brought over from Sri Lanka and was installed in the chedi by HRH Crown Prince Maha Vajiralongkorn.
The walls of the chedi contain mural paintings depicting scenes from the Jataka, the tales about the previous lives of the Buddha. A large number of Buddha images is kept inside the three story chedi.