One of my favourite things about Phoenix is the mountains that pop up out of nothing. Well, not nothing, really, but out of expanses of sand or suburbia. They grab your attention, and suggest that hey, maybe this isn't a sprawling city after all. Maybe this is still the 'Wild West.'
South Mountain is one of those natural phenomena, and, in fact, is one of the mountains that defines Phoenix. Houses sidle up to it from the north and south sides, but in between the mountain is blissfully, uncharacteristically undeveloped. Full of steep as well as flat hiking trails, a viewpoint on top (that you can drive to, if need be), and more saguaro cacti than burrito smears on your shirt, South Mountain is a natural, desert gem.
Not to be missed in the cooler times of year.