At least 4,000 people of all ages have been protesting against the building of nuclear power stations in Switzerland.
The rally comes amid discussions about where to dump nuclear waste and plans to build new atomic fuel plants.
The demonstration was called by more than 80 organisations for Whit Monday.
Marchers, including representatives from the centre-left Social Democratic Party and the Green Party, covered ten kilometres from Aarau to Olten, via the nuclear power station at Gösgen.
People even came from neighbouring countries, such as Germany, Swiss public television reported.
Participants called for more use of wind and solar energy, saying atomic power was “dinosaur technology”.
They also hailed the demonstration as the start of a new anti-nuclear movement in the country, such as was witnessed in the 1970s.
Leo Scherrer from Greenpeace Switzerland said the rally was an important step before a referendum on the building of new nuclear plants, which should take place in 2013.
swissinfo.ch and agencies