We are traveling at the same time on the Rhine & Moselle and are trying to decide on day trips from Basel also. We have contemplated Zurich, Geneva and the Biel/Bien area--but have not made any decisions or arrangements. Are you looking at traveling in Switzerland by train?
A good place to go is Interlaken. This touristy town is the gateway to the Bernese Alps, one of the most spectacular groups of mountains in Switzerland. You can take a series of trains and cable cars from there to the top of the Jungfrau if you want to get the view from the top. This is time consuming and expensive. The mountains may also be covered in clouds (there were when we were there - we only saw them for a little while).
If you don't want to go to the top, consider taking the train to Thun (at the opposite end of Lake Thun from Interlaken). Thun has a nice castle museum. You can then take the ferry from Thun to Interlaken. Stop off at Oberhofen to see the excellent castle museum there before going on to Interlaken. You can then take the train back from Interlaken.
For more details, check Rick Steves' guidebooks and videos.
Comments
If you don't want to go to the top, consider taking the train to Thun (at the opposite end of Lake Thun from Interlaken). Thun has a nice castle museum. You can then take the ferry from Thun to Interlaken. Stop off at Oberhofen to see the excellent castle museum there before going on to Interlaken. You can then take the train back from Interlaken.
For more details, check Rick Steves' guidebooks and videos.