Vista do Signal de Sauvabelin

The Signal de Sauvabelin also offers a beautiful view of the city and the surrounding area. In the Middle Ages, guards were posted here day and night, kept watch and warned the population of enemy attacks ... a pile of wood was always ready for this, which was set on fire when the alarm was triggered.
Source lausanne.ch/de/thematiques/loisirs-et-detente/pour-les-lutins/balades-et-visites/balades-thematiques/balade-insolite-de-sauvabelin-a-la-cite .html
The view is beautiful, the nearby restaurant is not praised by the locals, so take something with you for a picnic.

Nice view of Lake Geneva and its surrounding mountains

This vantage point offers a vast panoramic view over the city and its surroundings. You can see: The two towers of the cathedral, Set against the background of the lake.

The two towers of the cathedral, set against the background of the lake, are revealed from this spot. It also offers broad panoramic views across the city and surrounding area. The name of the site is also closely tied to this ample vista. Indeed, many centuries ago, a watch would be posted there to act as look-out and signal the arrival of approaching enemies. In more recent times, two celebrities who resided just a stone’s throw away were able to feast on this romantic view: the fashion designer Coco Chanel in the late 1960s and the singer David Bowie in the 1980s and 1990s.From the look-out post, take the only downhill path, then the one that descends immediately to your left. Lower down, near a large left-hand bend, make your way down to the left. Behind the trees, you will be able to make out a large meadow, with tall grass in the summer months. Head down across the meadow via a pretty grassy path that leads you to an orchard. Lower down, you soon find yourself at the “Fondation de l’Hermitage”, an art gallery housed in a historic mansion and a nearby outbuilding. Allow yourself some time in the English gardens on the lake side.

(lausanne-tourisme.ch/en/P10612/at-the-signal-de-sauvabelin)