Fosse Dionne in Tonnerre
A natural French spring in Tonnerre, built into a haunting grotto since Roman times and converted into a washhouse in 1758.

šŸ“œ Ancient wellspring in Tonnerre, France, built into a haunting grotto since Roman times.
šŸ” A Vaucluse spring with a varied but perpetual flow, converted into a washhouse in 1758. Its origin remains a mystery, explored to 61m depth.

Why Go

šŸŒŠ Mysterious natural spring with varied flow, its origin still a secret.
šŸ›ļø Historic Roman and medieval constructions.
šŸ“ø Picturesque grotto, tranquil and evocative, with crumbling masonry and moss.
šŸš¶ Easy access for self-guided tours available all year.

Why Avoid

āš ļø Diving access is restricted due to past fatalities.

Tips

ā˜€ļø Water flow is gentle in summer, more vigorous in spring due to snow melt.
šŸ—£ļø Staff speak French, English, and Spanish for group visits.
šŸ¾ Pets are welcome.

Cost

šŸ’° Free self-guided visits.

Hours

šŸ•’ Self-guided tours: all year round. Group visits: by prior arrangement.

Last updated 1 day ago

We strive for accuracy, but errors may occur. Please verify key info.