Pierre du Bigot

Pierre du Bigot is a boulder covered in prehistoric carvings, sitting on the Mûrier hill in the town of Saint-Martin-d'Hères, just a few kilometers from Grenoble in the Isère department. It's one of the lesser-known but genuinely fascinating traces of the Neolithic era in the Dauphiné region.

What exactly is this stone?

The block is a glacial erratic — a piece of rock carried and deposited by a glacier — made of pink granite laced with mica schist. It measures roughly two meters long and one and a half meters high, with an estimated volume of four cubic meters. Its rounded edges and flat upper surface are what make it stand out: that surface bears 46 cupules, small bowl-shaped depressions typical of Stone Age rock art. Researchers date these carvings to somewhere between 7000 and 4000 BCE.

How was it discovered?

The stone owes its recognition to Hippolyte Müller, an archaeologist and ethnographer active in the Grenoble area at the turn of the 20th century. He found it on March 12, 1911, and presented his findings to the French Prehistoric Society just eleven days later, on March 23. Müller was the one who first recorded the block's dimensions, its rock composition, and the number of cupules on its surface.

Can you actually visit it?

Here's the honest answer: Pierre du Bigot sits on private land in the small hamlet of Bigot, so it isn't a public tourist site and you shouldn't step onto the property without the owners' permission. If you want to learn more without trespassing, head instead to the Musée dauphinois in Grenoble, which holds documentation and information about the stone — it's the best way to explore the topic respectfully.

What else can you pair with a visit to the area?

Saint-Martin-d'Hères sits within the greater Grenoble area, ringed by the Vercors, Belledonne, and Chartreuse massifs, so the region itself offers plenty of hiking trails and scenic viewpoints. The Mûrier hill, where the Bigot hamlet lies, is part of a local nature trail network — look for marked paths running along the Bigot stream valley, from which you can take in the landscape without crossing onto private land. It's an easy way to combine a short walk with a trip into Grenoble itself, where the historic center and the cable car up to the Bastille fortress are both worth the detour.

When's the best time to go?

Spring and autumn are the best seasons for exploring the greater Grenoble area, with mild temperatures and trails around the Mûrier hill that aren't baking in summer sun. Summer gets hot but opens up longer excursions into the higher parts of the surrounding massifs. In winter, it's better to focus on Grenoble itself and its museums, since the suburban trails can turn slippery after rain or snow.

Frequently asked questions

Is Pierre du Bigot an officially protected heritage site? The stone has been known to researchers since 1911 and is documented in prehistoric literature about the Grenoble area, though it sits on private property rather than in an open public space.

Who discovered the stone, and when? Archaeologist Hippolyte Müller discovered it on March 12, 1911, and presented his findings to the French Prehistoric Society eleven days later, on March 23, 1911.

What are the cupules carved into the stone? They're 46 small, round depressions hand-carved into the rock during the Neolithic period. Their exact ritual or symbolic purpose hasn't been conclusively established by researchers.

Where can I learn more if I can't see the stone in person? The Musée dauphinois in Grenoble is the best resource, holding material related to the stone's discovery and characteristics.