Inside the airy building of Wat Tham Phra Phutthasaiyat, natural rock formations adorn the cave walls with various Buddha images, both reclining and meditating, along with paintings and statues of revered monks for worship. The building's pillars are decorated with slate, complementing the serene and tranquil atmosphere, reflecting a perfect blend of faith and the unique geological features of Sakon Nakhon province.