Wat That Mahachai It is the enshrined place of Phra That Mahachai which is one of the important precursors of Nakhon Phanom province and well-respected by the people of Pla Pak district. It is a place containing the relics of the Arahant with Luang Pu Khamphan Kosapanyo, former abbot of Wat That Mahachai, was the leader in the construction of the relics. Inside, there is also the largest Buddha image carved with sweet neem wood in Thailand. It is a relic on the birthday of those born on Wednesday (daytime) believes that the merits of those who come to worship will result in the achievement of work progress as desired. He was a coordinator of the ten directions, good speech, rich trading in the Ubosot; it has the principal Buddha image named Phra Phutthachaisit. There is also the largest Buddha image carved in sweet neem wood in Thailand, and mural paintings in the Ubosot showing the history of the Buddha, which has a very beautiful artistic pattern in the northeastern region.