Hole in the Rock: the quickest, easiest sightseeing possible in Phoenix.
A friend came to visit and was just staying overnight until lunch the next day. We were going to be in the Scottsday/Tempe area so I figured at the very least I should take her over to Papago Park to see some of the native plants and the cool looking, bumpy red mountains.
I had never been to Hole in a Rock, but I had always seen people standing up there every time I drive by the park. I had no idea how they got up there though. So I was pleasantly surprised to find out that it is ridiculously easy. Half hour to get up to and down from the hole, stairs carved into the mountain the whole way up and a beautiful view from either side.
We went at 10:30 in the morning so we were all alone up there, which was even better.