A "bone chapel" is a type of ossuary, a place where human skeletal remains are stored. These chapels often contain the bones of thousands of individuals, arranged in artistic patterns or displayed in unique ways. They serve as a reminder of mortality and are often found in historical sites across Europe. One of the most famous examples is the Bone Chapel of Sedlec in the Czech Republic, which features elaborate decorations made from human bones. Such chapels were created due to space constraints in cemeteries and the desire to honor the deceased while also addressing the practical needs of burial practices.