Swiss Ice Caves

There is one at the Jungfraujoch (Top of Europe) complex. It's a walk-thru, museum-style ice cave. You take the only train that runs to the top, which boards in Lauterbrunnen, just south of Interlaken. Takes an hour or more to get up there. I know I've seen some on TV where you can drink vodka and things like that - might not be in Switzerland though.

If you do opt to visit Jungfrau, make sure you get up early, allow a minimum of two or three hours at the top and start to come down long BEFORE the last train(s). The last trains from Jungfrau can be packed and trying to get on, nevermind getting a seat can be a hassle. You can stop enroute at any of the transfer stations (there are two different routes to the top from Interlaken both requiring two changes), be certain to check train times, but don't do this on the way up, go straight up and take a leisurely ride back down, being careful not to miss the last train to the town were your accomodation is . You can get a discount on the rail tickets if you have a Swiss rail pass.

The ice caves are at the top of the Jungfrau. It's actually part of the glacier that's outside the window of the Jungfraujoch. It's a walkthrough museum type with cut-in displays along the way. It's a bit cool in there as you might imagine. The train trip up and down takes 2 hours each way from Lauterbrunnen. You change trains at Kleine Scheidegg. The R/T fare from Interlaken Ost is 186CHF ($238). From Lauterbrunnen, it's slightly less. In the Lauterbrunnen train station there's a live TV camera so that you can check the weather up there. Also, the first run up has a lower fare (or at least it used to). Go early for the best blue sky. It can get cloudy in the afternoon as does the Schilthorn if you go up there.

Was just in the Ice Cave at Jungfrau. Get a HALFCard swiss pass - it will save 50% or so. I also stayed in WENGEN which is on the way up - get in early or make a reservation the day before (they start at 10am tho and I wanted to go at 830-9ish).
Lots to do up there - so leave plenty of time if you want to go for a walk to one of the huts on the snow/glacier. Well marked but its about a 35-45 min walk one way at 10k feet! They serve indian and korean food now too hah!

i see most responders are mentioning the same place on Jungfrau. Isn't it odd that Switzerland with sooo many Alps doesnt have more ice caves open to tourists ??? Here is a neat cave tho not an Ice cave. Lac Souterrain the underground lake of St Leonard. Its an underground cave with a boat ride on the lake inside. Located 6km east of the city of Sion on route 9

The Jungfraujoch ice palace may be the only mentioned here, but it is not the only one in Switzerland. There is the Eispavillion at Saas-Fee, the biggest ice grotto in the world, at Allalin at 3,500 m above sea-level. Mt. Titile (above Engelberg) has an ice cave you can reach by the Rotair lift.