3 days left - what should I choose?

Hi,
going with my father we had heart surgery. After staying 4 nights in Lauterbrunnen on July we will have 3 nights left as flying back from Zurich. We will have swiss pass.
About my father - He can hike on flat or very moderate down (6-10 km). I'm not sure what are the heights he can do I guess as 2,300 meters (as the air pressure inside an airplane).
He prefer places with live atmosphere at the evenings. I would like to do some easy hikes in mountains for few hours and basically everyday see nature in half of most of the day (except the evening maybe).
Also he prefer a place which is not too hot during day (since it is July).
I thouth of few options and not sure what is the best:

1. Zermatt - can go for a few cable cars and stay in village or take day trips to villages around.
I'm afraid of the steep up and downs there as I've heard.

2. Lucerne - not touring the city but maybe cuises on the lake, Rigi mountain and maybe some hikes you can advice me.

3. Train Trip -
First Day - Take the golden pass from interlaken to Lucern, maybe take a cruise and continue to Chur to arrive at the evening (problem - we are with suitcases during the day).
Second Day - Leave our suitcase in our hotel for storage. Take the Bernina Express until the stop before Tirano. Stay the night there, maybe some flat hikes??
Third Day - Take the Bernina again or a regular train to Chur while stopping in the way (Alp Grum, St Morits etc). Stay the Night in Chur.
Take the train to Zurich in the morning and the flight is during evening (20:00). Alternatively, we go to Lucern.

4. Around GSTAAD - flat hikes but might be too warm.

Please advise.

Hi guest25,

Lucerne can be pretty warm in summer. Gstaad is better, but Zermatt and St. Moritz are normally the coolest places. St. Moritz would be a good option: it's 1,800 m above see level, so not too warm even in July. It's less isolated than Zermatt; you can make day trips in all directions. There are lots of hiking trails at the valley floor which are relatively flat. Some are not the most impressive trails as the better views are higher up, but you'll see the mountains in all cases.

Some examples:

• Pontresina - Samedan
• Ospizio Bernina - Alp Grüm: this is high up in the mountains but fairly flat, except for the very last short section.
• Morteratch glacier: this is a very gradual ascend, and you'd take the same trail back.
• Muottas Muragl - Alp Languard: high up in the mountains and great views. I recall this one as fairly flat as well.
• Spinas to Bever.
• Maloja to Sils (along the lake).

Most rail stations have lockers or a luggage department to store suitcases. You can also have your suitcases transported for you. Hotels near the St. Moritz rail station can be found here. La Margna Swiss Quality Hotel is very close to the rail station. Hotel Bellaval is practically at the station. Most other hotels are further away and uphill.

I hope this helps you out!