Fosse Dionne - the karst spring located in the center of Tonnerre, France.

© bbsferrari/Getty Images/iStockphoto

Fosse Dionne

Yonne


Some 200L of water per second gushes from Fosse Dionne, a natural spring near the centre of Tonnerre that was sacred to the Celts and whose vivid blue-green tint hints at its great depth. Legend has it that a serpent lurks at the bottom. Forming a picturesque backdrop behind the great circular pool are a mid-18th-century washing house, a semicircle of ancient homes and a steep forested hillside.


Lonely Planet's must-see attractions

Nearby Yonne attractions

1. Hôtel-Dieu

0.21 MILES

This charity hospital, founded in 1293 by Marguerite de Bourgogne (wife of Charles d’Anjou), is most famous for its vast, barrel-vaulted patients' hall…

2. Musée Chevalier d'Éon

0.32 MILES

Tonnerre's newest attraction is this house-museum, once home to the colourful Chevalier d'Éon, a gender-bending 18th-century diplomat and spy. The…

3. Château de Tanlay

5.36 MILES

Dominating the northern edge of the tranquil riverside village of Tanlay, the elegant French Renaissance-style Château de Tanlay is surrounded by a wide…

4. Synagogue

8.41 MILES

For a free tour of this lovingly restored 16th-century synagogue, just knock on the door during regular opening hours.

5. Église St-Martin

8.42 MILES

The 12th- and 13th-century Gothic Église St-Martin, first founded in the 9th century by monks fleeing the Norman attacks on Tours, is two short blocks…

6. Petit Pontigny

8.46 MILES

The 12th-century cellar of Petit Pontigny (viewable from the exterior only) was once used by Pontigny's Cistercian monks to ferment wine.

7. Château d'Ancy-le-Franc

10.57 MILES

The Italian Renaissance makes a cameo appearance at this imposing château, built in the 1540s by celebrated Italian architect Serlio. The richly painted…

8. Château de Maulnes

11.58 MILES

The only château in France built on a pentagonal plan, and buttressed by five towers, the Renaissance-era Château de Maulnes, 24km east of Tonnerre, is a…