When excavating the floor of a building, archeologists may typically uncover ancient earthenware tiles or a beautiful Roman mosaic.
But a team in the Netherlands have uncovered a much more bizarre find – a floor of bones.
The meticulously-arranged bones were found inside a building at Achterdam, a red light district in the Dutch city of Alkmaar.
Taken from dead cattle, the bones might have been laid about 500 years ago during construction of the building, the experts think.
However, the bones were laid centuries before Achterdam became famous as a red light district.
The municipality of Alkmaar, Gemeente Alkmaar, said in a statement: ‘The question is of course why bones were used to fill the tiled floor.
‘Tiles were not particularly expensive and were often used. It is possible that the bones were placed there for a special reason.
‘Perhaps because it fitted in well with the craft that was probably practiced here. It could also have been a cheap way of filling.’
The careful arrangement of bones could have been done in absence of the requisite number of tiles or to fill a hole created by damage
Achterdam is a red light district in the Dutch city of Alkmaar, about 18 miles (30km) north of capital Amsterdam. Pictured, the building where the bone floor was found
Experts at the city’s heritage service had been conducting renovations in the house – which was built in 1609 – when they found the bones.
The bones had been covered with a thin layer of loam – soil that is a mixture of sand, silt, and clay – which was then covered by a recent tile floor.
The exact period in which the bones were laid is still being investigated, but the experts estimate that it could be as far back as the 15th century.
‘The building itself was constructed in 1609,’ Nancy de Jong, archaeologist for the municipality of Alkmaar, told MailOnline.
‘But it’s possible that the foundations and the lower level of the floor where the bones were found are much older.
‘It is common for houses to be built on older foundations.’
Alkmaar is thought to date back about 1,000 years, as the earliest mention of the city is in a 10th-century document.
The bones are metacarpals and metatarsals from the lower limbs of cattle, all cut to the same height – but why exactly they were used instead of tiles is unclear.
According to experts, the bones will be further investigated to see if there are any clues as to how this floor was used
During archaeological research at the Achterdam in the centre of Alkmaar, archaeologists from the municipality found part of a floor made of animal bones
The addition of the carefully-arranged bones could have been done in absence of the requisite number of tiles, or to fill a hole created by damage.
‘We were very happy to have the chance to see this bone floor with our own eyes,’ said de Jong.
‘It is always a privilege to uncover something from a long-gone era and add new information to the history of Alkmaar.’
While the historical use of bones in this way is unusual, it is not unprecedented in the Netherlands – but only in the northern province of North Holland.
In the past, these types of floors have been found in the cities of Hoorn, Enkhuizen and Edam – which, like Alkmaar, are in North Holland.
In the Hoorn example, the vertically placed bones have also been used in combination with a tiled floor, suggesting it was a deliberate tactic used by North Holland tilers.
According to experts, the bones will be further investigated to see if there are any clues as to how exactly this floor was used.
Anjo van de Ven, heritage councilor at Gemeente Alkmaar, said: ‘Discovering this floor is incredibly interesting.
Achterdam (pictured) – a 490-foot street with window prostitution on both sides- is located in the middle of the old centre of Alkmaar
‘There are still so many hidden stories, waiting for our team of archaeologists to come and find them.’
Achterdam – a 490-foot street with window prostitution on both sides – is located in the middle of the old centre of Alkmaar, well known for its traditional cheese market.
Since the Middle Ages people could go for paid sex in Alkmaar, although at the time the city’s red light district was the Vrouwenstraat (Women’s Street) slightly further south.
The Christian church considered sex work objectionable, but also necessary to protect other women against rape and virginity.
in 1973, the first brothel on the Achterdam – at that time still a street that mainly accommodated traditional craftsmen such as barrel makers, hat makers and rope makers – was opened.
This was the starting point of Achterdam as a red light district, which is the only place in Alkmaar where window prostitution is permitted.
Unfortunately, Achterdam has since been the site of trafficking and even the murder of two prostitutes in 1996, although since the turn of the century, rooms may only be operated with a permit from the municipality.