The most important temple of Nakhon Si Thammarat and southern Thailand. It was constructed at the time of the founding of
the town, and contains a tooth relic of Buddha. The 55.78 m high chedi is surrounded by 173 smaller ones. According to the legend of Phra Borom That Nakhon Si Thammarat, Prince Thanakuman and Queen Hem Chala brought Buddha relics to Hat Sai Kaeo and built a small pagoda to mark the location. Later on, King Si-Thamma Sokarat established the city of Nakhon Si Thammarat and built a new pagoda.

While the chedi is now in Sri Lankan style, it is said to be built on top of an earlier Srivijaya style chedi. The chedi completed a renovation in early 2009.

At the base of the chedi is a gallery named Wihan Tap Kaset, decorated with many Buddha statues and elephant heads emerging from the chedi. Wihan Phra Song Ma is the buildings which contains the staircase which leads to a walkway around the chedi above the gallery. At the bottom of the staircase are demon giants (yak) as guardians. Adjoining to the north is the Wihan Kien,
which contains a small temple museum.

South of the chedi is the large ubosot building, the Wihan Luang. Monk living quarters are located across the street in a separate temple, Wat Na Phra Boromathat.