We're attending a family wedding in Italy in early June, and decided to fly into in Zurich then make our way via train to Florence in time for the festivities. We have about 7 days to accomplish this. We want to focus on exploring Switzerland (we've travelled all over Italy), but are not sure which area. We like the idea of picking 1 or 2 "home base" cities/towns where we can do day trips by train to surrounding areas. I'm more interested in mountains and small towns rather than city tours, and doing some light hiking and bike riding. I would like if possible to do part or all of the Bernina Express and Glacier Express train trips. Maybe 2 days exploring Zurich then head down towards Bern and Interlaken? Your thoughts and suggestions are much appreciated!
The Three Panorama express trains criss-cross Switzerland. They are each about a full-day trip so you may have to pick and choose, and it may be hard to do several from only "base" towns. Zurich to St Moritz takes about 3 1/2hours. Zermatt is about 2 3/4 hours back to Lauterbrunnen, which is the entrance to the Bernese Oberland.
https://www.sbb.ch/en/leisure-holidays/travel-in-switzerland/panoramareisen.html
Zurich and Lucerne are relatively close together so getting back and forth around there is easy enough. Among other things Zurich has the Swiss National Museum with an outstanding archeological presentations, and the Frauenkirche which has wonderful Marc Chagall windows. Lucerne has the lovely lakefront and fine museums, trams up the Pilatus and opportunities to visit Mt Rigi.
Hiking can be almost anywhere, but is particularly wonderful in the Bernese Oberland 2 1/2 hours west of Lucerne.
Working backwards from Florence, you could go to Florence from Lugano/Como area at the south end of the Gotthard Panorama express that begins in Lucerne (which includes a cruise down the Lake of Lucerne into the core of the Alps before taking the train over the Gotthard Pass on the old rail route). Head to Lucerne for that trip after several days in the Oberland. And head to the Oberland from Zermatt after the Glacier express trip from St Moritz, and start be going from Zurich to St Moritz. All of this requires a lot of train travel though.
Have a great time.
You only have 7 days, and I see 3 of those as long travel days if you want to do those scenic train trips.
Day 1. Arrive at Zurich airport and go immediately to Lauterbrunnen (or better Wengen or Muerren). Jet lag recovery.
Day 2. Enjoy the Berner Oberland.
Day 3. Enjoy the Berner Oberland.
Day 4. Enjoy the Berner Oberland.
Day 5. Train to Brig (dep ~8:30, arr ~10:40 to get the Glacier Express (11:18) to Samedan (5:29 pm) then bus to Pontresina (5:45 pm).
Day 6. Enjoy the Engadine.
Day 7. Take the Bernina Express from Pontresina (9:52) to Tirano (12:00) followed by lunch, then the regional train (1:08 pm) to Milano Centrale (3:40 pm) then Freccia train (4:10 pm) to Florence (6:04 pm).
You could head straight to Lucerne for 2 or 3 nights, then onto Murren (Bernese Oberland) for 4 or 5 nights. Lucerne is a super cute small city. Murren is up in the Alps with tons of hiking and lifts to get you around. Then make your way to Milan by train (several changes), then to Florence. Look at the SBB website for train schedules, it quite easy. I have not done the "express" trains, so I can't give any advice on them, but they look pretty cool.