During a building renovation in Alkmaar, Netherlands, archaeologists discovered a centuries-old tile floor filled with cow bones. The find, dating potentially to the 15th century, has puzzled researchers due to the abundance of cow bones, and their use as a filler material, especially since tiles were inexpensive at the time. The discovery is adding a new layer to the rich history of Alkmaar, known for its cheese market. Further investigations are underway to determine the purpose and extent of the bone-filled floor.