Tower in Interlaken and Luzern

For Interlaken, no, most of the buildings are only a few stories. If you can get in, there might be a decent view from the upper floors of one of the old grand hotels.

The tallest building in Interlaken is the Metropole Hotel, there's probably a restaurant on the top floor. It's a modern building the TI office is located on the ground floor.

Luzern has most of the ancient wall that used to surround the city. You can get some great pictures of the city from there.

The best place in Interlaken is the hotel mentioned previously. There is a deck on the top floor overlooking the park in front where the daredevils land their parachutes. Interlaken is just OK for an afternoon. You can see the whole place in just a few hours or less. Don't stay there, go further up the Alps for much better scenery and ambience. the best views in Luzern are along the river.

The only reason to even be in Interlaken is to change trains IMO. It is full of tacky shops and there are casinos. The old hotels looked elegant but the hotel restaurants seemed to be very expensive. The old town section of Interlaken was mildly interesting and we enjoyed an old restaurant there called The Baren. The real Switzerland is the Berner Oberland and we were so glad we stayed in Wengen--a perfect choice--with the perfect view from our hotel window: the Jungfrau, Eiger, and Monch.

Along with Tommy and Susan, I'd say, don't waste time on Interlaken. Even from the highest structural point you will not get much of a view of the mountains. You've got to go to someplace like Murren for the fantastic views. As Susan said, the old wall in Lucerne will give you great views of the city. You can walk along the top of the wall a ways. I think it's a must-do activity in Lucerne. Go in the morning or evening for the best light.

Thank you all for the suggestions. We have been in Lauterbrunnen for the past 3 days enjoying BO and hiking. We were considering going to Interlaken today, but are going to drop the plan after reading the responses. We are going to ask the locals in the hotel to suggest some easy hikes for us for today since the last 3 days have gotten us sore. BO is gorgeous and hiking in the Alps is a dream!

Simran, thanks for the trip report and glad you're having a good time hiking in the Lauterbrunnen Valley. Hiking there is a dream, isn't it!?

Simran is that you I keep seeing on the web-cams in the Berner Oberland? Just being funny. I am glad you like it there. My turn comes up in exactly one month and I can already smell the mountain air.
How about going to First and hiking to the lake there? Unless you have done it already.