Alternatives: tomb-house, pl∙ tomb-houses
A house-like tomb, often designed as a tiny chapel or praying site; sepulcher; charnel house.
The edge of the new glowy patch almost touches the place, or rather the structure, to which I have the keys. A little building, to be quite precise. It's the Geldersmann family's ancestral tombhouse. (Source: J∙ Okram - The Mystery of the Rammed Key.)