The Paris Catacombs (also known as The Catacombs and The World's Largest Grave) are underground ossuaries in Paris containing remains of over six million Parisians in a small part of the ancient Mines of Paris tunnel network to deal with both cave-ins and overflowing cemeteries.
The Ghostbusters and Lieutenant Philip Constantin ventured underground and moved through the catacombs rather than risk disturbing the slime covering the exterior of the Louvre Museum and being detected. Relying mostly on Constantin's experience navigating the catacombs in his youth. Constantin revealed he would be escorting them through the Louvre on the President's orders to ensure the art exhibits' survival.
- On page 2 of Ghostbusters International #5, Lieutenant Constantin admits to being a cataphile, the term given to those obsessed with the Paris catacombs
- Lieutenant Constantin alludes to the French National Police's cataflics who started to patrol the catacombs after it was deemed illegal to descend them in 1955.
- On page 3 of Ghostbusters International #5, in panel 1, Winston's light shines on the arranged ossements, famous stacks of bones in the Paris Catacombs started by Louis-Étienne Héricart de Thury, head of the Paris Mine Inspection Service from 1810.