I have always enjoyed long walks - perhaps why I have never been deterred by the walking tour aspect of Mercat.
Those of you who are new to Edinburgh, or even those of you who live here and tend to stick indoors - Arthur's Seat is where it's at! Seriously. It is one of the nicest places I have ever been, and right in the city centre. You don't need to go to the top, you can stay on a path all the way around, there are hares (or rabbits? A distinction that has long evaded me), and did I mention the multiple lakes/ponds?
Recommended: up and along the Crags - the cliff face (not for the faint of the heart) but then again neither are ghost tours- and then down through the valley. Even in bad weather, it is worth the trip, although if the wind is blowing up a gale you may want to avoid the summit...
So if going on a tour and tramping up and down the Royal Mile hasn't completely worn you out, make your way up or around Arthur's Seat!