They got some positive comments on TA so I hope that you hear from someone.
But, if you tell us where you are thinking of your interests we might be able to help you. There are number of people who have posted on this forum who do not drive. I've done trips with cars and without and know that you can see a lot without the car. The places that are more difficult to travel to without a car include the Western Isles, the Northern Isles and the west and north in general. That said, there are still some wonderful train trips and judicious use of buses can get you around. One of the most beautiful train trips is from Inverness to Kyle of Lochalsh. I've had friends make a day of taking the train to Plockton (a few stops east of Kyle of Lochalsh) exploring Plockton and returning to Inverness. Here are some other places that are easily reached by train.
- Dunkeld/Birnam--Lovely small town with a good pub, nice walks along the Tay and into the hills. Ancient Cathedral. Nice for photography.
- Pitlochry--Festival Theatre, Explorer's Garden, two distilleries (one closer than the other, but both walkable), more walks along the Tay.
- Blair Castle--great castle nestled in the Cairngorms.
- Aviemore--This is Toni's favorite. She says that there is lots to do without a car. I've walked in the area and the mountains are beautiful. It's likely possible to get a bus or taxi to some of the local walks in the Cairngorms.
- Inverness--Culloden is reachable by public bus. There are also many day tours offered out of the tourist information center. There are excellent restaurants. I like Cawdor castle, which may be accessible by bus, but is easy to get there by taxi. They have wonderful gardens that I love photographing. The day trips include: Orkney (not one I would do, but a lot of people like it), Skye, Urquhart Castle and more.
- Fort William and on to Mallaig--FW is pretty touristy, but the train ride from there to Mallaig is beautiful. Also, you can likely get a bus or taxi to some of the local glens. I went to Glen Nevis and spent a lovely afternoon photographing the stream and glen.
- Glasgow and Edinburgh--these two cities are less than an hour apart by train.
- St. Andrew's--the last mile or two is by bus, but it's a common day tour.
- Stirling--This is an easy train ride from either Edinburgh or Glasgow. It's a walk up to the castle, but no doubt there are buses and taxis if you're not up for the walk up hill.
There are more, but these are the ones that come to mind for me.