The Shiva Linga pedestals, or “Yoni bases,” found in Lopburi’s historical sites, including Phra Prang Sam Yod, are crucial evidence of the transition between Hinduism and Buddhism. These stone bases typically feature a square shape with a drainage channel known as a “Somasutra,” used to direct holy water poured over the Shiva Linga in Shaivism rituals. Such artifacts confirm that Phra Prang Sam Yod and nearby ruins might have served as Hindu shrines before being converted into Buddhist temples in later periods. The pedestals are usually crafted from sandstone or green sandstone, materials durable enough to carry intricate carvings based on ancient Khmer cosmological beliefs. In some areas, only the Yoni base remains without the Linga, often due to religious purges or relocations as beliefs shifted toward Theravada Buddhism over the centuries. Today, some of these bases remain in their original positions or have been collected for younger generations to study the layered religious history of Lopburi.