Although it sounds more like the working title for the next Saw movie, buildings lined with human bones really do exist. Known as ossuaries these bizarre sites can be found all around the world and, as well as acting as a grim reminder of our own mortality, they are also strangely fascinating, with many attracting thousands of tourists every year.

Frequently used where burial space is limited, ossuaries make it possible to store the remains of thousands of people in a single tomb and often feature bones and skulls stacked in elaborate patterns on the walls and floors. Here are several examples of these macabre sites.

Amazing Buildings Made of Bones

The Skull Tower of Niš, Serbia

A monument to 19th century Serbian rebels, The Skull Tower was constructed in 1809, during the Serbian uprising against the Ottoman Empire. A total of 952 skulls were embedded in the tower to act as a warning to anyone who dared to oppose the Ottoman Empire. Most were eventually pried out and returned to the families of the dead, but 58 skulls still remain today.

Sedlec Ossuary, Czech Republic

The Sedlec Ossuary, also known as 'The Bone Church', is located in the Czech Republic and is without doubt one of the most incredible collections of human bones in the world. This fascinating ossuary is contains the bones of between 40,000 and 70,000 people; but even more fascinating is the fact that many of the bones have been artistically arranged. Some of the more striking features include a giant coat of arms and a strangely beautiful bone chandelier which includes one of every bone found in the human body.

Kaplica Czaszek, Poland

Built in 1776, Kaplica Czaszek, or the 'Chapel of Skulls', is located in Czermna, Poland. After noticing human skulls protruding from the slope near the chapel bell tower, Czech priest Vaclav Tomaszek and a local gravedigger decided to excavate the area. Amazed by the large quantities of human bones they uncovered (believed to the victims of several wars and epidemics) the pair exhumed the bones and skulls of around 24,000 people, tightly stacking them into the walls and vaulting of the chapel. After completing their masterpiece both the priest and gravedigger decided that, after their death, they too should be laid to rest in the 'Chapel of Skulls'.

Capela dos Ossos, Portugal

Built in the 16th century the Capela dos Ossos also known as the 'Chapel of Bones' as it translates in English is one of the most popular attractions in the city of Évora and gets its gruesome name due to the interior walls decorated with human bones. Supposedly created to inspire people to communicate the inevitability of death the Capela dos Ossos was originally built to handle the overflow from local cemeteries. As well as thousands of human bones two desiccated bodies can also be seen chained to the wall. Visitors to the chapel are greeted by the warning translates as 'We bones, lying here bare, are awaiting yours'.

Santa Maria della Concezione dei Cappuccini, Italy

Located in Rome this church is most famously known as an ossuary in which are displayed the remains of over 4,000 Capuchin friars artistically arranged in 5 crypts. What makes this ossuary different from those described above is that several of the bodies remain complete skeletons; some dressed in Capuchin robes and one holding a scythe and a set of scales. A plaque in the church reads bluntly "What you are now, we once were; what we are now, you shall be."

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