The "Bone Church," officially known as the Sedlec Ossuary, is a small chapel located in Kutná Hora, Czech Republic. It is famous for its unique interior, which is decorated with human bones, estimated to be the remains of around 40,000 to 70,000 people. The ossuary was created in the 14th century and serves as a reminder of the inevitability of death. The bones are arranged in artistic displays, including a large chandelier made entirely of bones and several decorative elements. The chapel attracts visitors from around the world, who come to witness this macabre yet fascinating site that reflects the historical significance of medieval Europe and its views on mortality.