The aim of this work was to document and analyze an exceptionally preserved mummified body of a six-year-old boy found in a family tomb in Skalná, Czech Republic. The boy died of scarlet fever in 1887, and was buried under ground in a cemetery in an unknown coffin shortly after death. His parents exhumed his cadaver and entombed it in the family crypt in two tin coffins a year later. This secondary burial and violent opening of the coffins in the end of the World War II leaving the body exposed to external climatic conditions led to its natural (spontaneous) dry mummification. The computed tomography scan of the corpse showed that the majority of internal organs were well preserved. And surprisingly, parts of the central nervous system estimated to be about 70% of the original size with distinguishable neural structures. We tested the cerebellum, tentorium and hair for mercury and arsenic, and the body was assessed by a forensic examiner for possible signs of an artificial embalming, and pathology. We did not confirm the hypothesis of the eventual preservation using the salts of mercury and/or arsenic or other fixation common for embalming in the 1800s. The anthropogenic mummification can be excluded due to the presence of fly larvae, historical records confirmed the burial of the individual right after death, and the different degree of organs condition. It appears that the unique preservation of the mummy and its internal organs was most likely caused by stable conditions of the environment.