A unique discovery was made by archaeologists in the vicinity of the red-light district: a chilling floor constructed from bones.

In an unusual neighborhood, a centuries-old floor made of animal bones was recently discovered by Dutch archaeologists.

An archaeological organization in Alkmaar, Netherlands, announced the discovery of a floor in a 16th century building in the red-light district of Achterdam on Dec. 13.

Heritage Alkmaar believes that the floor of the house, built in 1609, may be even older, possibly an earlier foundation built in the 15th century. The bone floor was discovered by archaeologists and came as a surprise to them.

Heritage Alkmaar wrote that the old floor is not particularly noteworthy, but what is remarkable is that some tiles are missing and those areas are filled with a floor made of bones.

Officials claim that all the bones on the floor were from cattle. Prior to this discovery, floors constructed from animal bones had only been found in the Dutch cities of Hoorn, Enkhuizen, and Edam.

"This type of floor is extremely rare and has only been found in North Holland," the archaeological organization stated. "Therefore, this discovery is truly exceptional."

The bones in the floor were cut at the same height, as Heritage Alkmaar pointed out.

The organization noted that the bones appeared to be used as filler for the floor's holes, despite the apparent pattern.

"The bones are arranged in two planes, with the top side facing up in one and the sawed underside exposed in the other."

Archaeologist Nancy de Jong expressed her "joy" upon witnessing the archaeological discovery.

She stated that it is always a privilege to reveal information from the past and contribute to the history of Alkmaar.