Fontaine d'Orchaise

Fontaine d'Orchaise is a karst cave and spring system in Orchaise, a village that today forms part of the merged commune of Valencisse in the Loir-et-Cher department, close to Blois and right along the Cisse river. Carved out of Senonian chalk studded with flint nodules, it ranks among the more extensive and interesting caves in the Centre-Val de Loire region.

What does the cave look like underground?

Roughly 1,175 metres of galleries have been surveyed so far, with a vertical range of about 13 metres. The system runs on two levels. The lower one is the active network: an underground river still flows through it and resurfaces as the spring (the "fontaine") that feeds the Cisse. The upper level, known locally as the Grotte aux Renards ("foxes' cave"), is the fossil network — a dry set of passages shaped by an older, higher course of water, complete with erosion meanders and displaced rock blocks left behind once the river cut down to its present level.

What is the history behind it?

The earliest record of activity at the site dates to 1682, when clay from the cave was dug out for pottery use. The first proper exploration accounts come from 1825, when visitors reportedly pushed about 170 metres in from the entrance. Toward the end of the 19th century, the terminal stretch of the underground river was fitted with hydraulic works, and the site supplied the village with water right up until the early 1950s.

Can visitors go inside?

Access is restricted. Entering the cave requires prior authorization from the town hall (mairie), and it is granted only to licensed cavers with proper equipment and insurance — this is not a walk-in attraction. Local caving clubs, including one based in Blois, do organize occasional open visits, most often timed to the national caving and canyoning open days (Journées Nationales de la Spéléologie et du Canyon), which is the practical way for non-cavers to see the interior.

Is there anything to see without going underground?

Even without entering, the site is worth a stop: the point where the underground river resurfaces into the Cisse makes for an attractive spot along the riverbank. The surrounding commune of Valencisse — created in 2016 from the merger of Orchaise and Molineuf, joined in 2017 by Chambon-sur-Cisse — sits in a quiet, rural stretch of the Loire Valley within easy reach of the châteaux around Blois.

FAQ

Where exactly is Fontaine d'Orchaise? In Orchaise, a village that is now a constituent part of the commune of Valencisse, Loir-et-Cher department, on the Cisse river near Blois.

Is the cave open to the public? Not freely. Entry needs authorization from the mairie and is limited to licensed speleologists. The public can see it during occasional visits organized by local caving clubs.

What is the difference between the active and fossil networks? The active network is the lower level, where an underground river still flows and feeds the spring. The fossil network is the upper, dry level (Grotte aux Renards), a relic of an earlier, higher water course.

Is "Valencisse" the correct commune name? Yes. Valencisse is a merged commune created in 2016 from Orchaise and Molineuf, with Chambon-sur-Cisse added in 2017. Orchaise, where the cave sits, is now a delegated village within Valencisse.