Phra Pathom Chedi, located in Nakhon Pathom Province, is a first-class royal temple and one of Thailand's most significant Buddhist landmarks. Standing 120.45 meters tall, it is the largest and tallest stupa in Thailand. The current chedi, built in the Sri Lankan style during King Rama IV's reign, encloses earlier stupas of Indian and Khmer designs.

The chedi enshrines relics of Lord Buddha and has historical ties to the Dvaravati period. Historians believe the original chedi may have been influenced by Buddhist emissaries from Emperor Ashoka. Annual festivals, lasting nine days and nights, are held in the 12th lunar month to honor the site.

Phra Pathom Chedi's design features a bell-shaped stupa, brick construction, and ceramic tiles, surrounded by a double-tiered gallery and four-directional halls. It also houses historical artifacts, including a seated Buddha statue from the Dvaravati period. The site is deeply revered by Buddhists worldwide.

The temple also holds the royal ashes of King Rama VI, Queen Suvadhana, and Princess Petcharat Ratchasuda behind the Phra Ruang Rojanarith statue in the northern hall.