I recently went on holiday to the Isle Of Lewis, but did used to live there before I went to college.
It is one of the most beautiful, clean places I have ever been. We drove up through Skye, to Tarbert then up through Harris to Lewis. We stayed in Uig on the west coast of Lewis for half of the week, then went to Stornoway - the main town - for the remainder of the week. The west coast has some of the most amazing beaches, Uig Sands - the sea is miles away when it's out. Port of Ness on the tip of the Island another very clean beach. You don't have to worry about glass and rubbish, there is very little of either on the beaches.
Lewis has the Callanish Standing Stones - a formation of stones which are believed to be spiritual, Carloway Broch - I'm not quite sure what a broch is, I think it's a house. It's famous for it's Chessmen. It has fantastic views where ever you go on the island.
Stornoway is the main town, it has a war memorial and countless gift shops, it's not very big, but is a pretty town. I think if you go and don't have transport, unless you are planning a walking holiday then it's not a good idea, public transport is limited it 1 or 2 buses a day to & from places.
If you have transport or are planning a walking holiday then there are countless places to explore, with gift/craft shops/tea shops & restaurants tucked away all over the place. Some of the places are very remote and empty. We haven't been everywhere despite living there.
The locals are very helpful if you are a tourist (I got stuck in the soft sand had to wait for a local & a tractor to pull me out). The cost of food & petrol is much higher than on the main land.