Carrière du chemin de Port-Mahon, Medieval underground quarry in 14th arrondissement, France.

Carrière du chemin de Port-Mahon is a limestone quarry beneath Tombe-Issoire Street in the 14th arrondissement with two levels of galleries carved using medieval extraction methods from the fourteenth century. The walls still show clear traces of this early stonework, easily distinguished from inscriptions added later by subsequent miners.

Stone extraction here is documented before 1492, not from that year. In 1994 the quarry was classified as a monument historique, and four years later the Conseil d'État confirmed the ruling, noting that this fourteenth-century underground quarry is the only one truly attested from that period beneath Paris and shows intact medieval stone-working. In 1815 it featured among the attractions of the catacombs tour.

The quarry takes its name from sculptures that Antoine Décure, a quarry worker, carved in the catacombs galleries, depicting Port-Mahon on Minorca. Visitors to the catacombs can see these carvings, and a few metres from them a closed gate bars the way into the Port-Mahon quarry galleries.

The quarry lies beneath 26-30 rue de la Tombe-Issoire and 15-17 villa Saint-Jacques, in the 14th arrondissement. It is closed to visitors: from the Catacombs route, a locked gate a few metres from Décure's sculptures blocks the way in. Since 2003 it has belonged to a property developer, and heritage groups have contested the building plans in court.

In 1815 the quarry was listed among the attractions of the Catacombs tour, before the gate now closing it off from Décure's sculptures was put in place. Since 2003 it has belonged to a property developer who wants to sink foundations into the galleries and build several buildings above; heritage associations have contested the project in court.