Nice easy hike to the Hole in the Rock. We had our 3 and 6 year old and they had no problems getting to the hole. There is a path along the left side that has steps. There are smaller pebbles throughout that makes the path a bit slippery at times so go up slowly and watch your step. On the way back down we went the opposite way. It wasn't an actual pathway but it was still easy nevertheless, plus we got to see the hole from a different viewpoint.
The view from the top is amazing! You can see Papago Park, the Phoenix Zoo, ASU campus, and the airport. Go at sunrise or sunset for best views. We actually parked in the zoo parking lot but there are smaller parking lots closer to the trail head. Parking was free but we got there around 5:40pm, after zoo was already closed. We didn't see any place to pay for parking either so I'm guessing that it's always free.