PARIS (AP) — The tunnels zigzagging through limestone were created to provide building materials for Paris. Then they became the damp home to vast subterranean mushroom farms. Now, deep beneath the city's largest park, the quarry is usually off-limits, deemed too dangerous for regular visitors.
Unescorted spelunkers face a 60-euro ($65) fine, but on Wednesday the 20-meter (66-foot) spiral staircase leading down into the earth from the Bois de Vincennes was briefly opened to journalists. Temperatures are a constant 13 degrees Celsius (55 Fahrenheit) and humidity hovers around a swampy 90 percent.
The four-hectare (10-acre) limestone quarry beneath Vincennes is one of several that helped build Paris. From the Middle Ages to 1860 workers toiled underground, mining and fashioning blocks of limestone.
This quarry is "one of the most interesting because it remains in its natural state," said Florence Cavailee, who is something of a spokeswoman for the city's underground heritage. Unlike other quarries that have been renovated or opened to tourists, the tunnels underneath Vincennes still look essentially as they did in the 19th century, she said.
During the 12th and 13th centuries Paris' population spiked, along with the demand for stone to build churches like the Notre Dame Cathedral, prompting deeper underground exploration.
Most of the work -- even the block-carving -- was done inside the galleries themselves, Cavaillee said, because the stone was easier to cut in the high humidity.
The Vincennes quarry once had seven worksites running at the same time. Overexploitation prompted the city to close its quarries in the late 19th century, fearing potential stability issues. The commercialization of concrete further triggered the abandonment of the industry.
From then on, until about 1950, the underground cavities took on a new role as plots for mushroom cultivation.
"Mushrooms were really a specialty of Paris," Cavailee said.