This might sound silly, but the coolest thing we did was visit a cooperage-- barrel makers. The story of those whiskey barrels is kind of amazing (the wood is 30 - 50 years old by the time they put whisky in it!), and the process of turning the old wood into new barrels, still done in the traditional style, is fascinating.
That's a Highland thing. The Highlands in general are beautiful. Go to Inverness, take the kid to Loch Ness. Make sure to see some of those shaggy Highland cows. I can't remember any names, but there are some old estates where you can tour the house; your kid might get a kick out of the less-modern ones, see how people used to live.
And of course, Culloden, the battlefield of the last Highland uprising against the English, where the clans were destroyed and the Highlands subjugated under English rule. It's a big open field, with boulders to mark each clan that fell. It's eerie, and moving.
For you, if you haven't already, read Outlander, by Diana Gabaldon. I love reading the fiction associated with a place I'm going to visit, and this is a fun, fast-moving novel that will give you a sense of what Scotland and the Scots used to be.
The food is pretty bad, btw. I generally quite like English food, and thought Scottish food was lousy. Haggis is tasty, as a breakfast meat. Black pudding, too. Just don't think real hard about
what it is.

Fish & chips are generally a good bet.