Geneva is probably the most international city in Switzerland: several global organisations (e.g. United Nations, World Trade Organisation & Red Cross) and corporations have their head quarters here. For tourists the Jet d´Eau ("water fountain"), the many quality watch stores, the large Lake and the vicinity to France are most obvious.
Interlaken is located in the heart of the Bernese Alps Interlaken is very well visited by tourists. And with good reason. The vicinity to the mountains, the abundance of activities, the unique location between Lake Thun and Lake Brienz and the excellent shopping make this a place well worth visiting. From here it is a short trip to Grindelwald or Lauterbrunnen for more scenery, waterfalls and the Jungfraujoch.
Most international visitors will make a stop in Luzern. The city offers the old Kapellbrücke as well as old buildings, murals, houses, souvenirs shops, a stone lion and lots more. Just around the corner are the Vierwaldtstättersee (aka Lake Lucerne) and the mountains with Rigi, Pilatus and Titlis the best known.
Zürich is the financial capital and largest city of Switzerland. You'll find the head quarters of major banks, insurances etc here. Tourists may like the old city, the lake and summer festivals. The "Gold Coast" hosts several international celebrities.
Montreux is located at the east end of Lake Geneva and just West of the Bernese Alps. Chillon Castle and Charles Chaplin's museum can be found here. Once a year there is the world famous jazz festival. Yes, there is lots to do.
Bern is the capital and political center of Switzerland. Furthermore it is a beautiful place both for visitors and residents. The old city is preserved and listed on UNESCO. Don´t miss the clock tower around noon, the cathedral or the bears in their bear park. Or just enjoy watching a game of chess in front of the government building with kids splashing in the fountains...
St. Moritz is known for the Olympic games, the movies that it appeared in and the international jet-set that lives here. This is an exclusive and expensive place! There is some special fun here in winter: alpine skiing, walking and the horse race over the lake. St. Moritz is part of the Graubünden area, where people speak "Romantsch", the 4th official language of Switzerland.
Locarno is located in the Italian part of Switzerland and best known for its film festival. But there is more than that. The Lago Maggiore offers many water activities and neighbouring cities like Ascona and Bellinzona are also worth your visit.