What is the little black house in Thailand?

A huge garden museum. The little black house in Thailand is a huge garden museum. It is not a temple, so it can't be called a black house. It's just that all the buildings are based on black and are composed of several Thai temples with log structure. There are a large number of exhibits about death and hell, which combine ancient animal bones, primitive hunting tools, antiques and specimens with modern artistic techniques, confirming that the exhibition theme of the museum is hell and death.