It wouldn't cross your mind, that from the centre of Montreux, and passing beneath the bridges of the highway, there are gorgues like the 'Gorges du Chauderon'. It is an easy walk, but with strong vertical slope. The path is very walkable, it is full of stairs to help us with the ascencion. The change of vegetation changes a lot from the bottom part that reaches Montreux where it seems more like a tropical forest, and the top part is more typically swiss.
A simple 40 minute route from the train station of la Saraz. The climb is of about 100 metres. In 40 minutes you arrive at the dam. Its a magical place filled with energy from the forest fairies. There are two dams and a small beach. The water doesn't seem too clean, but its from the amount of organic matter there is in the forest.
If you feel like taking a walk after lunch at Saint-Cergue.. there is a walk you can take, called 'le sentier Ballade à Béatrix'. It is welll indicated, with 16 points of information. It starts with a little steeply, but the forest is very pleasant, the views from the old castle are impressive, the invisible ruins, and it goes through a series of rocky formations with interesting caves.
A simple route, strongly recommended, with very little uphill.
We start at the camping place of Vallorbe, with a strong vertical slope untin we cross the col. From there, we descend through a minor road until Vailion. After crossing the village we enter once more at the forest, where we cross a defensive system (the toblerones) where we start once more to descend, following the river. In the last part, we walk next to the river and cross wooden bridges several times.