Rossens dam: the 83-metre wall that created Lake Gruyère

The structure that gave birth to a lake

A lake thirteen kilometres long does not fall from the sky. Lake Gruyère was born of a building site: the Rossens dam, completed in 1948, an 83-metre concrete wall set across the Sarine. Behind it the water rose, the valley disappeared and the landscape we know today took shape, islands included. Standing in front of the structure, you grasp the scale of the undertaking at a glance, and understand why the Île d'Ogoz is surrounded by water today when it once stood on a hill. The installation is operated by Groupe E, which runs guided tours and devotes a page to the spectacular water releases at the dam.

What your children will discover

They discover the sheer scale first: 83 metres is the height of a twenty-storey building, and the eye only reaches the foot of the wall at the cost of real vertigo. Then they understand the principle, which can be told in two sentences: you block a river, the water builds up, and its fall produces electricity. Finally they see the result with their own eyes, that immense lake that begins just behind. Along the path they pass through forest, open viewpoints and, if they pay attention, the wildlife of the shore.

What you do there and the atmosphere on site

You come to look at the structure, and you stay for the walk. From the dam, a path follows the lake along the left bank, through the forest overlooking the water: allow 2.3 kilometres there and back to a picnic table, an ideal format with children. The dam footbridge, very close by, lets you round off the outing with a spectacular crossing above the lake. The atmosphere is that of a technical site open onto nature: no ticket office and no shop, just a path, a forest and a view.

Before you go

• Recommended age: from 4 years old for the lakeside walk
• Duration: about an hour for the 2.3 kilometres there and back
• Price: surroundings and walk free; guided tours of the structure free on request
• Booking: guided tours are booked with Groupe E, from ten people
• Pushchair accessibility: forest path, practicality to be assessed on site
• Transport: by car via the Route du Barrage
• Best season: all year; spring and autumn offer the finest light

Tips from parents

• Guided tours of the structure require a group of at least ten people: join up with other families or check the dates published by Groupe E via Electrobroc.
• Bring the picnic: the walk leads precisely to a table by the lake.
• Explain the principle of the dam before you arrive, children get far more out of the visit when they know what they are looking at.
• Keep the youngest away from the edges and follow the signs on this industrial site.
• Combine it with the dam footbridge and Pont-la-Ville Beach for a full day.

Useful information

• Address: Route du Barrage, 1728 Rossens
• Official website: https://www.groupe-e.ch/fr/rossens
• Opening hours: surroundings and trail freely accessible; guided tours according to the Groupe E schedule
• Access (transport): by car from Fribourg or Bulle; public transport connections to be checked on cff.ch

Why we recommend it

Because this is where Lake Gruyère makes complete sense: without this wall, it would not exist. The outing combines a spectacular object lesson, a short and easy walk by the water, and the chance to continue onto the suspended footbridge. Many children will never see a structure like it from so close.

In a nutshell

An 83-metre dam completed in 1948, the origin of Lake Gruyère, with a 2.3-kilometre family walk along the water and guided tours on request.