Anything we should stop and see along our route. We need to be in Geneva in the evening as we leave next morning for US.
Thought maybe something in Montreux or Lausanne. We could lock our luggage at the train station at one or both of the stops for a quick adventure.
From Interlaken to Montreux, will you be taking the scenic Golden Pass route? I would.
From the Explore Europe section of this site, here's a summary of lakeside areas that Rick covers in his book. Montreux and Lausanne train stations both have lockers. The Château de Chillon itself also has lockers but the nearest train station and boat dock do not.
▲▲▲ Château de Chillon: Medieval castle perched romantically on eastern shore of Lake Geneva, with climbable ramparts, damp dungeons, and literary history.
▲▲ Lausanne: Twisty, 3-D city stretching up a steep hill from the lakefront, with pleasant old town, plenty of sights — most notably the Olympic and Art Brut museums — and easy boat and train connections to the surrounding area.
▲ Montreux: Relaxed lakeside resort offering few sights — just sublime views of the misty lake and cut-glass peaks, and immediate access to the Golden Pass and Chocolate Train scenic rail lines.
If you are traveling by train you can get to the Chateau de Chillon via the Veytaux-Lutry stop on the local train line (may require a transfer). It's tiny but only 300m from the castle.
If you go to Lausanne, you can walk from the Gare to the shore at Ouchy. Or, take the metro down the hill (or up!). The Olympic Museum is a short stroll away. It's mainly memorabilia from famous athletes plus the history of the movement. If you have the time and the weather is good, take the ferry to Vevey and back. The views from the boat are quite good. You can also head up to the old town via the metro -- the Flon stop or above at the Riponne stop. You can also walk, but it's uphill all the way.
The Brut museum is quite unusual -- some people find it fascinating. It's a bit tougher to get to from the station.
In Montreux you can also take a bus to and from Chillon, we had a free bus pass since we were staying at a hotel so that's how we did it. The bus runs right next to the train.