Any favorite things to do in Montreux? We arrive late afternoon, have that night, the full next day and take an early train to the Geneva airport the third day. Thanks!
On arrival day, I would walk to the castle Chillon.
On your full day, either a tour of the vineyards around Vevey/Lausanne or a train up to a mountain hike. Look or the best activities for the season you are visiting here:
https://www.myswitzerland.com/en-us/destinations/montreux-riviera/
https://www.montreuxriviera.com/en/