In Scotland, Kilmartin Valley in Argyll is rammed with standing stones, cairns, chambered tombs and rock art. 'Tis the home of Temple Wood circle, the Great X, Achnabreck and Ormaig rock art panels, Dunadd and near by is Kintraw standing stone.... a week minimum is needed here to see everything...

http://www.themodernantiquarian.com/site/433

Clava Cairns is worth a visit too... a little touristy but if you're luck enough to get the place to yourself (nearby Culloden Battlefield tends to draw most of the tourists), it's lovely...

Glen Elg Brocks are nice and usually pretty quiet... the route over Bealach Mam Rattagan is stunning with a view over the Five Sisters of Kintail.

If you get the chance to push north, the area around Durness is worth a visit... very primeaval and wild with Golden Eagles, white beaches and turquoise seas... lovely!

The west coast has great scenery, but it's the east side that has the majority of the megalithic stuff.