Prang Ku is an ancient Khmer archaeological site of great historical and archaeological importance in northeastern Thailand. It is believed to have been built during the 18th Buddhist century in the reign of King Jayavarman VII of the Khmer Empire, a period when Khmer civilization reached its peak in the construction of religious monuments and public infrastructure, especially the Arokhayasala (ancient hospitals) established along transportation routes to provide both physical and spiritual healing. This concept reflects the ideology of the Dharmaraja, which emphasized not only political power but also the well-being and quality of life of the people in a systematic way.The architectural layout of Prang Ku follows Mahayana Buddhist cosmology, with the main sanctuary serving as the central sacred space. It stands on a large laterite base and faces east, symbolizing light, rebirth, and auspiciousness. The structure has a square plan with a single main entrance and three false doors, following Khmer architectural tradition that represents Mount Meru, the center of the universe in ancient belief. Inside the main sanctuary once enshrined an important Buddha image, reflecting the idea of the Buddha as a healer of both body and mind.

To the southeast of the main sanctuary is a library building (bannalai), which was used to store religious texts and important documents, highlighting the importance of knowledge and Dharma within the Arokhayasala system. The entire complex is enclosed by a laterite boundary wall that clearly separates the sacred space from the outside world, with a gopura (entrance gate) serving as the symbolic transition point from the secular world into a space of spirituality and healing.Outside the enclosure lies an ancient water reservoir (baray), which was used not only for ritual purposes but also symbolizes purity, the cleansing of illness, and the restoration of life energy. The overall arrangement of the Arokhayasala reflects not only architectural planning but also a deep integration of religious belief and cosmology, combining physical structure with spiritual meaning.

In terms of art, Prang Ku is classified under the Bayon style, a late Khmer artistic period characterized by simplicity combined with strong spiritual expression. Its stone carvings and architectural elements emphasize balance and solidity rather than ornamental complexity, reflecting a shift from monumental grandeur to humanitarian and healing-focused values.Today, the site has been restored and maintained by the Fine Arts Department of Thailand to preserve its historical and architectural significance. It serves as both an important cultural heritage site and an educational archaeological attraction in Chaiyaphum Province, allowing visitors not only to appreciate Khmer architectural beauty but also to understand the deep historical, cultural, and healing concepts embedded in the ancient civilization that continue to be evident today.