There is evidence that during the 19th century, families actually lived in the catacombs. In 1871 a group of monarchists were killed by communards in one of the chambers. During World War II, members of the French Resistance used the system of tunnels to hide out in, while at the same time in another part, German soldiers constructed an underground bunker (not part of the catacombs tour). Unofficial visits to the underground quarries of Paris are not permitted, especially as some areas can be very dangerous. However, secret entrances are scattered throughout Paris, accessed through the sewers or metro tunnels. There are also a number of manholes that lead into the catacombs.
The bones began accumulating in the catacombs in 1786, just as momentum for the Revolution was building in Paris. Land was becoming increasingly scarce and at the same time the cemeteries were becoming overcrowded. So the government of the time made the decision to move the remains of the dead to the empty limestone quarries, so freeing up the land presently being used as cemeteries for other use. While moving the remains from the cemeteries, no attempt was made to identify or separate individual bodies, but the bones were marked with a plaque specifying the cemetery they came from and the year when they were moved. The work was completed in 1860, by which time an an estimated five to six million skeletons had been relocated.
