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Routes
Bike touring routes & trails
France
Pays de la Loire
Saint-Nazaire
Prinquiau

The Blue Hole – Mabille Valley Lake loop from Prinquiau

Routes
Bike touring routes & trails
France
Pays de la Loire
Saint-Nazaire
Prinquiau

The Blue Hole – Mabille Valley Lake loop from Prinquiau

Moderate

5

riders

The Blue Hole – Mabille Valley Lake loop from Prinquiau

02:05

35.5km

170m

Cycling

Moderate bike ride. Good fitness required. Mostly paved surfaces. Suitable for all skill levels. The starting point of the route is accessible with public transport.

Last updated: May 22, 2026

Tips

Your route passes through protected areas

Please check local regulations for:

Parc naturel régional de Brière

Waypoints

A

Start point

Bus stop

Get Directions

1

9.04 km

The Blue Hole

Highlight • Structure

Three old granite quarries, abandoned in 1980, which naturally filled with water to form beautiful blue ponds, popular with fishermen. Many of the cobblestones of Nantes and Nazaire streets come from this place.

Translated by Google •

Tip by

2

9.30 km

Trou Bleu Viewpoint

Highlight • Viewpoint

Recently inaugurated, this new Loire viewpoint was built on the rocky promontory overlooking one of the ponds. It is accessed via a staircase carved into the rock, so bicycles must …

Translated by Google •

Tip by

3

10.9 km

The Port House

Highlight • Cafe

This beautiful residence, which currently houses a crêperie, served as a model for the Maison dans la Loire, a work that can be seen in Couëron.
The small port in …

Translated by Google •

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4

11.1 km

Lavau-sur-Loire

Highlight • Other

The old Saint-Martin du Sillon church has been listed as a historical monument since 1984.
Several beautiful old houses around this small town center.

Translated by Google •

Tip by

5

16.5 km

This small church is actually an extension of a 14th-century chapel, which is believed to be the current sacristy. The church in its present form was reportedly completed in 1606 …

Translated by Google •

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6

26.4 km

Mabille Valley Lake

Highlight • Other

The Lac de la Vallée Mabille, or Lac de Savenay, is a beautiful artificial reservoir that is worth a detour. By bike, you can easily go around the southern part …

Translated by Google •

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B

35.5 km

End point

Bus stop

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Way Types & Surfaces

Way Types

27.8 km

5.44 km

1.45 km

361 m

350 m

< 100 m

Surfaces

31.6 km

3.03 km

708 m

< 100 m

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Elevation

Elevation

Nothing selected – click and drag below to see the stats for a specific part of the route.

Highest point (90 m)

Lowest point (0 m)

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Weather

Powered by Foreca

Thursday 16 July

29°C

18°C

36 %

Additional weather tips

Max wind speed: 16.0 km/h

to get more detailed weather forecasts along your route

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