The first floor represents the underworld and contains precious artefacts from the founder, Lek Viriyaphant's personal collection. These include collections of tea sets, vases, and bowls, from the Ming Dynasty and Qing Dynasty. The underworld level also hosts the sculpture of the mythical being, a half Naga-half person, which was modeled after the belief that these beings guarded the precious treasures under the water.

** As many exhibits are very rare and precious, please do not take photos on this floor.