Grottes de Réclère, Natural cave system in Jura, Switzerland.

Grottes de Réclère is a show cave near the Franco-Swiss border in the Ajoie, west of Porrentruy, with about 1.5 km of passages. It lies at a col at 658 m on an east-west fold of the Jura between the Doubs valley and the Val de Réclère. The caves are the collapsed remnant of a cavity dissolved in fractured Rauracian limestone of the Upper Jurassic, about 155 million years old, during the folding of the Jura in the early Pliocene, 5 to 6 million years ago.

The vertical opening, known locally as Trou du Fahy, was long familiar to farmers, who used the shaft as a dump for domestic animal carcasses. The regional press reported the site's existence in 1889, and the caves were explored from that period onward. The passages formed when a cavity collapsed within the folded Rauracian limestone of the Jura.

The caves form part of the Préhisto-Parc, whose grounds hold 45 life-size reproductions of prehistoric animals. The name Trou du Fahy comes from the local farmers who knew the shaft before 1886 and used it as a dump for domestic animal carcasses. Visits to the caves are possible only with a guide.

The cave maintains a constant temperature around 7 degrees Celsius (45 degrees Fahrenheit), so warm clothing is necessary. The guided tour lasts about one hour and leads over 580 steps through the passages.

The cave's opening, a shaft pointing upward, was known to local farmers as the Trou du Fahy long before 1886; they used it as a dump for domestic animal carcasses. The caves were explored from 1886, and the regional press reported the site in 1889.